Weather Forecast For Reading & Berkshire

Welcome to the Spring weather forecast 2025, aimed at Reading & Berkshire though probably applicable to most of the south of England, as I talk quite broad brush.

I shall start with the usual caveat – seasonal forecasting can only be experimental, background signals can give an idea of what to expect, but notable events can override such signals.

It looks like we are about to have a sudden stratospheric warming event, which is annoying timing, both for the accuracy of this forecast and for the prospects of good spring weather.

This does mean that I’m less confident than normal – I’d rather be doing this forecast in two weeks time, and I may well do an updated version if the sudden stratospheric warming event happens (likely) and it upturns current expectations.

In any case, no seasonal forecast from any forecaster will be completely accurate, except if they get exceptionally lucky. My winter forecast was alright – both January and February were wetter than I expected, but high pressure was in control for much of February as I expected, just in a slightly different place. December’s forecast was pretty good. I wouldn’t give myself especially high marks.

Also I’d like to thank everyone that contributes, both in terms of comments on the Facebook posts and especially the photographs that are sent to me to use…the forecasts look much more boring without them.

And for this forecast, thanks to Donna for the cover photograph – a small donation to the charity of your choice will be made shortly.

Background Signals

Background signals tend to mean less in spring/summer, though the one overriding factor is the likely sudden stratospheric warming event.

Such events often (but not always) lead to high pressure blocks in positions that favour cold weather spreading down from the Arctic, or from Russia – so northerly or easterly winds.

Whilst a northerly flow will always be cooler/colder than normal at any time of year, easterly winds from around mid-April onwards can be warmer than normal, depending on the exact air source, and how much North Sea cloud is involved.

Effects from a sudden stratospheric warming (SWW) event tend to take 2-6 weeks to filter down into the troposphere (our level of the atmosphere).

Until the event has happened, and still it is possible that it is just a notable warming of the stratosphere and not an SSW, we can only talk in chances of something happening.

The other background signals include a weak La Niña and the QBO being in westerly phase, which should increase the chances of westerly flows. That said, these were also in affect during the winter, and we had reduced westerly flows compared to normal.

Conclusion? No idea.

March

Well let’s start with the bit I know – March will start sunny with overnight frost and/or fog, and temperatures will recover to a little above average. Something more showery likely for a time for the second week – mild or quite warm at first, possibly colder later.

Uncertainty increases notably for the second half. Something changeable broadly looks the theme, though with high pressure close by more often than not. Said high pressure more likely in milder positions, though brief cold snaps will remain possible, in the mix. Overnight frosts still possible. Some showers and occasional rain but overall probably more dry and sunny days, than showery days.

Overall I expect above-average temperatures, somewhat above-average sunshine and somewhat below-average rainfall.

Confidence level around 50% – pretty low compared to what I can normally feel.

April

Confidence really drops off a cliff now, due to the probable sudden stratospheric warming event, and the unknown outcomes – though outcomes more likely to favour cold flows than normal.

I was very confident of high pressure being in control for April until recently, but one effect of an SSW event can be for the Arctic air to go flooding south to our west, over the Atlantic, which then blows up large areas of low pressure – we saw this last winter where SSW events led to something milder and wetter.

But I’m going to stick to the more likely outcome, which is colder and drier weather with high pressure either to our north/north-west or west – allowing colder flows from the north or east for the first half of April.

Variable amounts of sunshine and cloud from day to day, some showers likely – some sleet/snow would be possible. Colder than normal conditions more likely, but brief quite warm spells could be mixed in too. Overnight frosts still possible.

I’d assume high pressure to continue to be fairly close by for the latter half of April, again some changeable conditions, some showers possible some days, though temperatures more likely to be average or above-average.

Overall I expect around average temperatures, slightly above-average sunshine and slightly below-average rainfall.

Confidence level just 20%. Damn that sudden stratospheric warming event.

May

By this point the effects of the SSW event (assuming it happened and assuming it was impactful) lessen. Should high pressure be to our north, the resulting easterly winds would be warm by this point – though should it be to our west, northerly flows still chilly.

My best guess is that high pressure will be to our north to allow easterly flows, so often warm and sunny, though not always, for the start of May. Cloud spilling in from the North Sea overnight and leading to cloudy mornings – or possibly cool and cloudy days, is possible, in such a set-up.

As the month goes on, heavy showers will tend to increase in prominence across the south of England, with low pressure tending to be close by to our south, over France. Potential for some decent thunderstorms (or indecent if you don’t care for them). Likely still warm/very warm with sunny spells.

Overall I expect above-average temperatures, slightly above-average sunshine amounts and an average number of days of rain – rainfall totals could be anything, depending on how heavy any downpours are.

Confidence level of 40%.

Summary And Early Summer Thoughts

Yikes…lots of uncertainty. May holds the most promise for those looking out for sunshine and warmth, though I do expect all 3 months to be sunnier than normal. Anything outstanding wet looks unlikely, though who knows what the effect of the SSW will be – all I can talk about is more likely outcomes for now.

I wish the SSW event happened two weeks earlier, or I did my forecast two weeks later. Alas. Maybe I’ll do an updated version in two weeks but I doubt I’ll have time.

Early summer thoughts are for a fairly hot first half/two-thirds of summer, though I’d still expect some heavy showers at times – early signals for August are looking notably wet. But that is a very, very, very long way away.

And that is your Spring Weather Forecast 2025. Thoughts?!

Welcome to the winter weather forecast 2024/25 for Reading & Berkshire.

Firstly the usual caveats – seasonal forecasting is difficult, no seasonal forecast will ever be 100% correct, as it is bound to events on a local and global scale.

Seasonal forecasting is done mostly on a global level, and also thought of in monthly terms – for example, the background signals and long-range models could suggest higher than normal pressure is likely one month, but that wouldn’t stop one week or more being under low pressure, and wet.

So you should always expect any seasonal forecast as a rough guide at best, and remember that I’m not a professional – just an amateur forecaster with a half-decent grip on what models are suggesting, and a decent writing ability.

My autumn forecast was…alright…I picked some things out correctly, for example the greater chance of northerly flows than normal in November, but then I also picked out a wet start to November, and it was dry.

Also a massive thanks to those who sent photographs in, and more so to those who do on a regular basis.

Thanks to Clare who’s photograph I’ve chosen – a small charity donation will be sent as a thank you, please let me know to whom.

Background Signals

Winter always has more impactful background signals than any other season, but that never is the whole story – events do and will deviate from this.

The Quasi-Biennial Oscillation is currently in westerly phase, which increases the chance of westerly winds, and hence milder, wetter conditions.

La Niña, though not the strongest, does tend to increase the chance of northerly flows in autumn and early winter (as we have already seen).

Sea surface temperatures around most of the UK, and especially to the west, are warmer than normal – so this will mean temperatures more likely to be higher than normal. However, to our north, sea surface temperatures are colder than normal – so northerly flows may have more impact in terms of cold than normal.

The Indian Ocean Dipole is forecast negative for the start of winter, which can increase the chances of colder northerly flows.

Finally, the Madden Julien Oscillation, which is only helpful (questionably so in my view) over the more medium-term, currently is forecasted to end up in phases which favour cold weather later in December.

A sudden stratospheric warming event (SSW) cannot be discounted, which is where the stratosphere (the atmospheric layer above our troposphere) suddenly warms, which can break apart the polar vortex and cause cold weather to flood down in our direction – the Beast From The East in 2018 being the classic example.

However, we had 3 such events last winter, a once in 250 years occurence – the first two arguably gave us much milder and wetter conditions, as the cold air from the Arctic, if I remember correctly, flooded south but to our west – and hitting the (relatively) warm Atlantic ocean caused large areas of low pressure – and the mild/wet conditions. And also caused the latter part of my winter forecast to fail!

And the third happened in March, too late for wintry weather but then caused a cooler than normal spring.

I’ve read arguments that La Niña combined with a westerly QBO increases the chance of an SSW occurring over winter…which is what we have. But not sure what to make of that.

So quite a lot of different background signals, but definitely some patterns including increased chances of northerly flows in early winter – as such it is time to start the forecast.

December

December looks a very variable month, especially to start. It should settle down after the first week, with temperatures around normal or a little below, though some showers possible in the easterly flow. Frost/fog will be possible.

After mid-month, something more changeable looks more likely with further heavy rain and strong winds at times – chances of more named storms, though temperatures most of the time above average – short colder snaps still possible.

Towards Christmas and into the New Year period, colder northerly flows become more possible, though westerly flows could still dominate. Expect changeable conditions, wind and rain at times, some sunnier and colder days too. Again, quite a mix seems most likely, though perhaps veering towards dry more than wet.

Overall I expect above average rainfall, around or slightly below-average sunshine, around average temperatures.

Confidence level 80%.

January

January again looks a fairly mixed month. The start of the month has greater chances of drier and colder weather, before becoming unsettled once more. Northerly flows very possible, named storms very possible.

In the second half of the month, something milder and changeable seems more likely – some rain at times, but also some dry spells, if perhaps cloudy and dry.

Overall I expect around average rainfall, slightly below-average sunshine, and slightly above-average temperatures.

Confidence level 60%.

February

Suggestions for February see higher than normal pressure over Europe, so something milder and drier than normal seems the more likely general outcome for the first half of the month – though some weather fronts will likely get through to bring some rain, albeit more limited amounts.

More likely it stays mild or very mild in the latter half of February, with dry conditions more likely than wet.

A sudden stratospheric warming event would increase the chance of cold and dry for February, considerably…but this is impossible to know at this stage.

Overall I expect rainfall to be below average, sunshine around or slightly-above average, temperatures above average, though with some uncertainty towards the end.

Confidence level 50%.

Summary And Early Spring Thoughts

So a pretty mixed winter seems more likely, though not quite as wet as it has been with high pressure playing more of a role than it has the last 18 months or so. Any cold spells more likely in the first 6 weeks of winter, and those from the north.

Early signs for spring, assuming no sudden stratospheric warming, are for a much warmer and drier first half of spring. Oh do hurry up!

And welcome to the rather delayed Autumn 2024 seasonal weather forecast for Reading & Berkshire – though it should broadly apply to much of southern England.

Let’s start with the usual caveat – seasonal forecasting is experimental, some of this forecast will be wrong. It is my best attempt at using background signals, long-range models, current patterns, and, well, vibes to establish a more likely route through the next 3 months.

Unexpected events can and do happen, and then throw off course the forecast.

Thanks also to Paul for the stunning photograph – a charity donation will be made to MS Society. Thanks to everyone who sent them in, and also to those sending them in for the usual twice-weekly posts – the forecast would be a lot more boring without them!

Background Signals

We are probably transitioning back into La Niña conditions, which would increase the chance of cooler north-westerly flows later in autumn.

The remnants of hurricanes can change our weather patterns when they recurve into the Atlantic, which adds uncertainly for September and to a lesser extent, October.

However the intertropical convergence zone has been further north than usual, which is thought to be hindering tropical storm development. I have no idea if this will continue.

Other than that, nothing really stands out as a background signal.

September

Well, September did start warm and unsettled, then went much cooler. That’s obviously not a forecast as I’m writing this on 12th September!

Warmer weather will quickly re-establish itself, with high pressure likely to build close to the north – allowing a warm easterly to develop. Sunshine amounts should be higher than normal, though some overnight low cloud feels likely on some days, which could take a while to clear.

Likewise in the final third of the month, low pressure may well develop to our south over Europe, with a chance of showers/thunderstorms moving north towards us at times.

Lower confidence by the end of the month, but something more unsettled and somewhat autumnal is more likely.

Overall rainfall amounts somewhat higher than average, sunshine amounts around average, temperatures somewhat higher than average.

Confidence level around 60%.

October

October looks likely to have quite a notable westerly flow. Possibly starting unsettled though more likely I think low pressure will become centred to the north of the UK, so we’ll tend to be dry much of the time in the south, relatively mild, sometimes sunny, perhaps even the odd warm day. Then occasional weather fronts bringing a bit of rain every 2/3/4 days – that kind of broad pattern. Windy at times.

Later in October, the more likely outcome seems to be that low pressure will be tracking further south, so areas of rain more frequent, heavier and more persistent, windy also – but still there should be some dry days too.

Overall rainfall amounts around average, sunshine amounts around average, temperatures slightly higher than average.

Confidence level around 50%.

November

During November, I expect the jetstream to be pushed further south, bringing some wet and windy/very windy conditions at first in November, but also a chance of some colder weather in between areas of rain.

In the latter half of November, more likely the jetstream is to our south and we see broadly drier, sunnier and colder weather – northerly (ish) flows more likely than normal, overnight frosts and perhaps wintry showers.

Overall rainfall amounts around average, sunshine amounts around average and temperatures slightly below average.

Confidence level around 50%.

Summary And Early Winter Thoughts

So a pretty mixed autumn – some wet spells but also some notably sunny periods too. I’m not foreseeing a constant washout of an autumn.

I’ve probably rushed the research of this compared to normal, so I’m a bit less confident, plus background signals seem pretty weak, but it will do for now.

Maybe in a few years, the AI models which are giving me increased confidence in the 7-10 day range, will be able to help with longer range forecasting…will be interesting!

Early winter thoughts are for a drier than normal winter – temperatures very dependent on positioning of high pressure systems, but assuming La Niña does develop, then cold spells very possible in December, a milder trend more likely in January/February but cold snaps still possible…of course, it is winter.

Full daily forecast tomorrow.

Summer has officially started, and it is time to issue my summer weather forecast 2024. There’s even a bit of sunshine today.

Usual disclaimer first, seasonal forecasting is experimental, nobody can tell you exactly what the weather will do in 42 day’s time. All I can offer is a broad based solution, based on background signals, recent weather patterns, long range weather models and a bit of guestimation.

Some of this will be right (well, hopefully!), some of it will be wrong. The aim is to get more broadly right than wrong – but one can have all the confidence one likes about the weather 3 months away, from strong background signals, weather models, etc – then an event happens that changes all that.

February this year was the perfect example – almost all background signals pointed to it being colder and drier than normal, weather models pointed that way too, the Met Office expected it, and still talked about it in February turning cold and dry. Yet it was ridiculously wet and mild…probably caused by the sudden stratospheric warming event in January, which in themselves normally cause cold and dry conditions.

My spring forecast had unusually low confidence behind it, and was pretty mixed in terms of success – arguably April/May turned out closer to the forecast than March. It was warmer and wetter than normal across all 3 months – I didn’t really pick that out, alas.

So take this with as much a pinch of salt as you want.

Also thanks to Debs for the photograph…had probably 10 that I wanted to use, so thanks to everyone that sent them in, but this is the closest to my forecast.

Background Signals

Background signals are less effectual in summer than winter, and there isn’t much to go on.

El Niño is fading into neutral ENSO conditions for summer, which I think favours reasonable weather in the UK, though with limited impact. We may transition to La Niña in August, but again I wouldn’t expect it to have much bearing on our weather.

North Atlantic sea surface temperatures remain well above normal, I think record levels – this will both increase heat when high pressure is in control, and rainfall intensity when low pressure is in control – especially if low pressure originates further south.

It’s also expected to be a busier than normal hurricane season – these are wild card events which can change the course of our weather patterns.

June

June looks fairly mixed. There is a fairly strong signal for high pressure to both dominant to our west, and also low pressure to our north/north-east, so this would suggest north-westerly flows more likely than normal for June.

The month starts fine and fairly warm. Towards the first weekend, it may become somewhat cooler and showery, though low certainty on this aspect. Probably not huge amounts of showers.

From then we likely alternate between cooler, cloudier spells with some showers and perhaps spells of wind/rain, and somewhat warmer spells with some sunshine.

During the latter third/quarter of June, a trend to something warmer but still with chances of showers – any showers heavier by this stage.

Overall I expect around average temperatures or even slightly below (rare in our warming world, if so), slightly below-average sunshine, and around average rainfall.

Confidence level 60%.

July

Fairly weak signals for July, but the beginning part of the month would be more likely to see further mixed conditions, some short hot/very hot spells mixed in, interspersed with heavy showers/thunderstorms on other days, and some fine warm/very warm days.

The latter half more likely drier, temperatures generally very warm or hot – though some short unsettled spells likely too – the mixed theme likely continues.

Overall I expect above average temperatures, around average sunshine, and slightly above average rainfall (though will depend on localised downpours…which will skew this).

Confidence level 50%.

August

What signals there are do suggest higher than normal pressure for August – which if this comes to pass (if!) may make a change from many recent summers.

Broadly still likely a mixture of conditions, many very warm/hot days, but also some wet/showery days as low pressure systems are triggered by the heat over Europe.

Suggestions that the latter part of August is a bit more of a westerly flow, and generally more settled, less hot, with reasonable sunny spells and only occasional weather fronts.

Overall I expect above average temperatures, slightly above average sunshine, and…well…rainfall totals could be anything depending if you catch a torrential downpour or two, so maybe days with rain falling is a better measure, and that to be below average.

Confidence level 50%.

Summary And Autumn

So…not bad. A pretty mixed but hotter than normal summer would be the general headline. But as I mentioned, the signals are weak, and I’ve been less successful with seasonal forecasts in recent years than I used to be. As always, take any weather forecast more than 5 day’s out with a huge bucket of salt.

Early suggestions for autumn are for it to be warmer, drier (!) and sunnier than normal, at least for September and October, with hot spells still probable.

Feel free to share this Summer Weather Forecast 2024, and enjoy your summer!

Spring has started, but its still pretty cold. Welcome to my weather forecast for Spring 2024.

First off, the usual caveat. Seasonal forecasting is difficult, if not impossible. It is mostly about studying background signals, previous year’s weather patterns, pattern matching and expectations of future background signals.

Events scupper this, as does a lack of understanding as to how conflicting background signals may work against each other. It’s pretty much best guesses.

This February was a great example. My forecast was for a colder and drier month than normal, based on background signals overwhelmingly pointing to this outcome being more likely, and also the chance of a sudden stratospheric warming being high, in my view.

Except we had the wettest and warmest February on record. What happened? Well, I assume events – it is often difficult to correlate what signal/event caused weather conditions, though I suspect the sudden stratospheric warming event counted against this time – whilst many lead to cold weather, some actually lead to milder conditions, and this SSW event was unusual in that it reflected back into the stratosphere and powered the stratospheric vortex, and hence we went into wet and mild overdrive. At least, I think that is the cause.

All of which is to say that some of this will be wrong, perhaps very wrong. But hopefully enough will be reasonably inline to make it valuable.

For December and January, my winter forecast behaved reasonably well – had February gone to expectations then I would have been very happy! Also I think I outlined future conditions in my twice-weekly forecasts with good levels of accuracy, quite often the pattern for 1-2 weeks ahead was clearer than normal. And I did drop the idea for a cold/dry February (or at least it turning so) earlier than the professionals did. So I’m content with my ongoing forecasts, if not the seasonal.

I am considering stopping doing these seasonal outlooks, because I question the value, especially when they go so off-course like February does. Feedback welcome – I’m not just looking for positive platitudes!

Finally thanks to Sarah for the photograph – a small donation has been made to The Brooke, as a thank you.

Background Signals

There’s always less influence from background signals in spring.

However, there is likely to be a third sudden stratospheric warming event in early March, or strong and early final warming of the stratospheric vortex – whatever it is classed as, this will increase the chance of easterly and/or northerly winds later in March, and into April – and also push the jetstream south.

It’s slightly annoying that I’m doing the forecast now, as in another week or so, after this stratospheric warming event, things will be clearer. So there’s more uncertainty in this forecast than normal.

El Niño should also increase the chance of cold and dry conditions, at least in March, though that was the case for February too and look what happened.

Easterly phase of the quasi-biennial oscillation should reduce the strength of westerly winds, and increase the chances of easterly flows.

Sea surface temperatures are likely to remain at record highs in the Atlantic, and my reading of this is that there will be more moisture in south-westerly flows, but also much more warmth potential to tap into – depending on if/when high pressure builds over Spain.

March

The sudden stratospheric warming event probably puts hopes for an early spring to bed, but not necessarily.

Most likely, March starts on the cold side, veers mildish then colder, showery days tending to drier days. Through the mid-month period easterly (ish) winds seem likely at times, which should make it colder at times, but also rain and milder weather will be pushing up from the south-west too. Where they meet, snow is possible – but chances do reduce of battleground snow in March, especially down here. A small chance of snow – nothing more.

Later in March, easterly or northerly winds are more likely, so conditions generally on the chilly side with overnight frost probable at times. Otherwise some sunshine, some light/moderate showers, perhaps wintry and some outright cloudy/chilly days. Occasionally, milder and wetter conditions will push up from the south-west.

Quite a mix really – and it will depend on where exactly high pressure sets up to our north (assuming it does) – so an outright wet month is plausible instead, but also a dry and cold month is too. My forecast is for a mixture of the two, with quite a bit of fluctuation.

Overall I expect temperatures to be slightly below-average, rainfall around average and sunshine slightly below-average.

Confidence level around 40% – lower than normal, due to the expected sudden stratospheric warming event in early March.

April

Assuming the stratospheric warming event happens, and the outcome is blocking highs to our north, then I expect April to start fairly chilly with showers or rain at times, with northerly or north-easterly winds being more likely than normal. Overnight frosts still very possible.

There is a weak signal for high pressure to build over Spain in the second half of April, perhaps slightly earlier, so I’m going with that, and suggesting that will increase the chance of warmth (finally!) in the second half of April. Unlikely to be an extended warm spell – likely mixed with some weather fronts bringing rain on a few days, some heavy showers on other days – but some warmer, sunny-ish days too.

Overall I expect temperatures to be around average – though a contrast between below-average to start the month, above-average to end, rainfall slightly above-average and sunshine around average.

Confidence level around 40% again.

May

Background signals really drop off here, and long-range models are conflicting with each other, so in a forecast with lower confidence than normal, I’m even lower on confidence for May.

My best suggestion is for the warmer than normal end of April to continue into the beginning of May, with some very pleasant days – though also a few interruptions – some showers, some occasional weak weather fronts bringing more cloud and rain, with fresher air following.

The latter part of May perhaps looks more unsettled for a time (possibly warm/humid still), though with a trend to much warmer and drier conditions by the end of the month.

Confidence level of 20% – unusually low.

Early summer thoughts and summary

So a mixed spring looks more likely, and not an especially joy-filled spring – with some colder and wetter conditions early. Though with the proviso that uncertainty is much higher than normal.

Early signals for summer do point to a drier and hotter summer being more likely than normal, particularly June.