Tag Archives: weather

Summer 2025 in Wanstead and beyond

The mean for summer 2025 in Wanstead finished 19.8C, 1.8C above the 1991-2020 average and the second warmest summer in a local record going back to 1797. The figure was just 0.2C short of the warmest summer in 2022.

It was a dry season; just 84.5mm of rain was recorded, the driest for three years and 21st driest to 1797.

Taking a broader view of Greater London, using Met Office statistics for St James’s Park and Heathrow, reveals that summer, as an average of the three, finished second warmest, just 0.174 behind 2022.

In terms of rainfall it finishest 22nd driest with an average of 92.2mm.

Some 590.5 hours of sunshine were measured at Heathrow, 105% of average and the sunniest for 3 years.

The very dry spring had already taken its toll on the Ornamental Waters, Wanstead Park

London winter forecast 2024/25

The coming winter is likely to be mild and wet overall thanks to a predominant south-westerly Atlantic regime.

While that may sound grim for any snow and cold lovers reading this I would suggest that the possibility of brief cold snaps this season are higher than they have been during the last few winters.

This year I have tried to improve my statistical method by adding warming on to previous years to, hopefully, give better results.

In terms of rainfall and mean temperature a total of eleven years were similar to this October and November, spanning 1826 to 2021.

The probabilities for the following DJF winter were thus.

Mean temperatureProbabilityRainfallProbability
Very mild46%Wet33%
Average to mild33%Average37%
Below average21%Dry30%

London winter forecast 2024/25

Looking deeper into the stats I had a look at the Oceanic Niño Index; no years were similar to this one though the index only goes as far back as 1950 – so no real help.

The prognosis for snow at this point seems bleak – though chances may be heightened should we experience a stratospheric sudden warming in December / January. Though, as seen in 1987 where a vortex ‘split’ was recorded, this would still not guarantee wintry weather.

Looking at the data month to month would suggest the best chance of a cold snap around December 22nd through Christmas before warming up in the New Year. Beyond that I would suggest that the chances of another cold snap in January are higher than they have been for the last few winters. February, however, looks very mild and possibly very wet.

Best I can do – have a good winter all!

Below is how I think each month will unfold.

Dec mean temperatureProbabilityRainfallProbability
Very mild64%Wet27%
Average to mild27%Average46%
Below average9%Dry27%
Jan mean temperatureProbabilityRainfallProbability
Very mild10%Wet17%
Average to mild45%Average28%
Below average45%Dry55%
Feb mean temperatureProbabilityRainfallProbability
Very mild64%Wet55%
Average to mild28%Average36%
Below average8%Dry9%

The ever wetter autumnal equinox

The period around the autumnal equinox appears to be getting wetter in this part of the UK.

Since 9am on Sunday 36mm has fallen at Wanstead, some 60% of the monthly total so far! Elsewhere, not too far away near Milton Keynes, Flitwick has recorded 124mm!

A look at the local stats shows that the week either side of September 22nd has been getting wetter since 2010.

A look at the rolling 10-year average since 1960 shows an increase since 2011.

London’s hottest heatwaves under the microscope

It is no surprise that London’s heatwaves are getting hotter but by what rate are they increasing?

Using a list of hot spells made nine years ago I set out to find how the 30-year trends have moved through the decades since 1852.

The mean of these hot spells has increased from 24.2C in 1851-1880 to 24.9 in 1991-2020, an increase of 0.7C.

Maxima during these spells, on the other hand, has decreased from 32.6C to 31.8C. It should be noted that the spell that produced this area’s hottest ever daily maximum, 40.1C on July 19th 2022, was a 2-day affair that didn’t qualify for the list.

It is the minima that produces the most notable results with average low temperatures increasing over 2C from 15.9C to 18C! The urban heat island in full effect although the estate where a large proportion of these stats are gathered has changed little since it was built in the early 1900s.

Rainfall during these hottest heatwaves is cyclical, in keeping with daily rainfall patterns observed over the same period.

Average sunshine in these heatwaves has shown a slight decline. It is no coincidence that maxima was at its highest during 1911-1950 when there was most sun. Increased cloud cover overall would take the edge off maxima while making the nights warmer.

UK rainfall: Seathwaite / Honister v London

It’s been a wet winter so far. Some 177mm has fallen in Wanstead – already 122 per cent more what falls in an average winter.

But the amount pales into comparison with the Lake District. Since December 1st 1360mm has fallen at Honister, a station close to Seathwaite which proudly proclaims itself as ‘England’s wettest place’.

Over a calendar year the area usually sees 5.6 times the amount of rainfall of London. However, this winter the total of 1360mm makes it 7.7 times wetter! A testament to just how persistent the SW’ly airstreams have been this season. And a reminder that the Lake District is the called the Lake District for a reason.

Data from the excellent Starlings Roost Weather.

Wanstead weather in December

Continuing on from last month this blog focuses on the weather recorded at this station over the last 11 years.

A look at the twelfth month shows some interesting trends…

The 9am air pressure readings were not included in previous climate summaries owing to analogue barometers only giving approximate air pressure readings. The advent of AWS has changed that, particularly for independent amateur observers.

A look at the below graphic shows pressure falling through the first half of the month. A sharp rise is then seen before falling again – there’s often storms around the 23rd until the 27th.

Average daily windrun is how much wind there’s been during a 24 hour period. The 23rd comes out as windiest.

Average rainfall shows precipitation building through the month, to peak on the 23rd before a sharp drop off after the 27th.

Average daily maximum temperatures during December show a stuttering first 10 days before a steady rise through the next fortnight before a steady fall off from the 23rd .

Average daily minima is up and down in the first 10 days before a steady rise from the 11th. Again there’s that falling off a cliff on the 23rd.
This pivotal date, being so close to Christmas Day, is one of the reasons why ‘will it, won’t it be a white Christmas’ is a perennial fascination among the nation.

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London winter forecast 2023/24

The coming winter is likely to be mild and wet thanks to a predominant south-westerly Atlantic regime.

This year I have tried to improve my statistical method by using historic data from across the capital thanks to the Met Office’s ever expanding library of data; daily Kew values now date back to 1881!

In terms of rainfall and mean temperature a total of eight years were similar to this October and November, spanning 1929 to 2020.

The probabilities for the following DJF winter were thus.

Mean temperatureProbabilityRainfallProbability
Very mild37%Wet37%
Average to mild51%Average63%
Below average12%Dry0%
London winter forecast 2023/24

Looking deeper into the stats I had a look at the Oceanic Niño Index; the most similar years to this one were 1982 and 1987.

A note on WeatherWeb mentions exception rainfall in the Lewes & Brighton area of Sussex, between 20th September and 31st December 1982.

January 1988 was the wettest in England and Wales for over 40 years, and the wettest at Hampstead since records began there in 1909.

February of that winter also saw a major storm affecting much of the British Isles on the 10th and 11th with much damage to buildings.

The prognosis for snow at this point seems bleak – though chances may be heightened should we experience a stratospheric sudden warming in December / January. Though, as seen in 1987 where a vortex ‘split’ was recorded, this would still not guarantee wintry weather.

Taking the above years into account would give a winter where the average mean would follow this graph. Therefore, after the cold snap during the first week of December, the temperature gradually climbs through the month until the 18th when the will be a gradual drop for a possible cold snap between Christmas and New Year.

This then followed by the usual warm up in the new year with changeable weather through January. The best chance of a sustained cold snap appears to be from February 7th to 13th.

Disturbed autumn regimes

October 18th this year heralded a run of weather where it has hardly stopped raining in this part of the south-east.

Since that date there has been 101mm of rain with 22 ‘rain days’, 24 hour periods where there’s been 0.2mm of rain or more. Just one of the last 24 days has been completely dry.

In terms of the 1991-2020 average the amount represents just under twice the usual amount of rainfall at this time of year.

In terms of unusual weather patterns it is up there amongst the ‘top 10’.

What does it mean for the coming winter. Impossible to say on a small scale but I’m guessing wet and mild in the south. Note however that 1960/61 and 1998/99 had a number of maritime northerly outbreaks which added up to an average winter in Scotland, and plenty of snow for the Highlands.

Also note how similar this autumn is to last year when the snowy spell in December came out of nowhere.

The Hampshire tornado of December 1821

While researching an incident of very low pressure in 1821 I also found this account of a tornado that happened a couple of days later – not dissimilar to events earlier this month close to the south coast of England.

In The Climate of London, Luke Howard writes about an account of an ‘electrical whirlwind’ or spout in Hampshire.

On December 27th, two days after the record low pressure recorded in the London area, residents between the towns of Alresford and Alton witnessed a thunderstorm that was accompanied by torrents of hail, rain and gusty winds at 2.30pm.

A funnel was seen tapering gradually to the ground, the vortex bending from the prevailing SW’ly wind. Lasting for two minutes, according to one account, the whirlwind caused havoc as it carved a ‘serpentine chiefly in the direction of London Road’.

Its effects were restricted to a distance of two miles along a path of varying between 6ft and 20 yards in width.

One person described the tornado as a body of thick white mist tapering from the clouds and near the earth about the size of a woolpack. It appeared to him to touch the earth and bound from it repeatedly. Another witness who was nearer said he felt as if pails of water were thrown on him such was the effect of the strong electric aura attending it though there was no discharge of water at the time from the cloud.

The aftermath revealed a trail of destruction. An oak tree, a ‘foot and a half’ in diameter, was broken and carried upwards of 40 yards. Several fences were removed to a distance of many feet.

In the village of Ropley a farmhouse was damaged two barns were destroyed. Large elm trees were uprooted, a ‘fine walnut tree broken in half’ and gates, stiles and even thick gate posts were torn up.

The trees and ruins blocked the coach road and ‘it required some hours labour to clear them away’.

Looking at the possible track of the tornado it occurred close to the UK’s ‘tornado alley’!

Wanstead weather in November

The current site hosting Wanstead’s weather station has been running for 11 years this month; the automatic station uploading data every 10 minutes to the internet.

The 10-year averages from the station are now good enough to be listed on the Climatological Observers Link.

A look at the eleventh month shows some interesting trends…

The 9am air pressure readings were not included in previous climate summaries owing to analogue barometers only giving approximate air pressure readings. The advent of AWS has changed that, particularly for independent amateur observers.

A look at the below graphic shows pressure lowest around the 4th, the stormiest weather of the month. Storm Ciaran in 2023 is proof of that.

Average daily windrun is how much wind there’s been during a 24 hour period. The 21st comes out as windiest, the date when in the past there has been some notable early snowfalls in the south of the UK.

Average rainfall shows most precipitation in the first two thirds of the month with the biggest fall of rain on the 19th.

Average daily maximum temperatures during November take a general decline but, again, there’s a notable fall away on the 20th.

Average daily minima decline to the 5th (the 6th is the median for the first air frost) before increasing before falling away again after mid month.