Tag Archives: East London weather statistics

London’s July extremes since 1959

With the ultra dry and warm month of June many feel the rest of summer will remain hot and dry. Recent weather patterns have seen much high pressure to our north keeping us dry and mostly sunny but protected from any humid Spanish plumes.

A look at local east London stats shows that half of the last 10 July months have been warmer than average while only two have been much drier than average.

I’ve put together a few top 10s of stats for Wanstead, St James’s Park and Heathrow for the month of July.

july1959WAN

july heathrow

sjp july

Some national UK July values according to TORRO

 

Hottest: 19th 2006: 36.5C at Wisley, Surrey.
Coldest: 15th 1977: -2.5C at Lagganlia, Highland.
Wettest: 18th 1955: 279.4.8mm at Martinstown Dorset.

july av mxIn terms of climatology July maxima, considering the 1981-2010 average, shows a fairly steady increase through the month, though around the 17th there is often a dip before a warm end. This would reflect the July heatwave singularity which occurs every year at 80 per cent probability.

The average rainfall graphic shows that downpour amounts are fairly random from year to year. The driest days are the 1st and the 25th. july av rn

 

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London’s June extremes since 1959

With the recent warms months of April and May you’d be forgiven for thinking that we’re in for a hot summer. Indeed the recent pattern of weather, would it repeat over the next month, could see many maxima records tumbling.

A look at local east London stats shows that six of the last 10 Junes have been warmer than average while half have been much drier than average.

I’ve put together a few top 10s of stats for Wanstead, St James’s Park and Heathrow for the month of June.

Probably most notable from the below values is that recent Junes have been devoid of extreme cool temperatures and rainfall.

Snow has been known to fall in June, in 1975.

Rain is usually most frequent in the last week of the month.

june extremes wans

heathrow june

june sjp

The 10 driest Junes were:

 

Some UK May values according to TORRO

Hottest: 29th 1957: 35.6C at Camden Square, London. Also Southampton 28th 1976
Coldest: 9th 1955: -5.6C at Dalwhinnie, Highland. Also June 1st and 3rd 1962: Santon Downham, Norfolk
Wettest: 28th 1917: 242.8mm at Bruton, Somerset

Screen Shot 2018-06-06 at 12.11.18In terms of climatology June maxima, considering the 1981-2010 average, shows a gradual increase through the month, though around the 19th to the 21st there is often a dip before a warm end. This would reflect the June Monsoon which occurs every year at 77 per cent probability.

The average rainfall graphic reflects this, showing a four-day wetter spell after the 20th.

Screen Shot 2018-06-06 at 12.29.10

 

 

 

 

London’s May extremes since 1959

Ne’er cast a clout till May is out. With the recent March and April weather being so variable it would be wise to bear in mind this old saying, especially with fine and warm weather forecast for the Bank Holiday weekend.

A look at local east London stats, however, shows that seven of the last 10 Mays have been warmer and drier than average.

I’ve put together a few top 10s of stats for Wanstead, St James’s Park and Heathrow for the month of April.

Probably most notable from the below values is that recent Mays have been devoid of extreme cool temperatures and rainfall.

With nights now relatively short air frosts are uncommon though the odd ground frost can still strike on a clear night.

Snow can fall in May – one example being 1979 in the higher parts of the capital – but after the first week it is extremely rare.

Rain is usually most frequent in the last week of the month.

wanstead may

SJP may

heathrow may

 

 

 

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Some UK May values according to TORRO

Hottest: 22nd 1922: 32.8C at Camden Square, London.
Coldest: 2nd 1917: -9.4C at Lynford, Norfolk
Wettest: 8th 1884: 172.2 at Seathwaite, Cumbria

 

In terms of climatology May maxima, considering the 1981-2010 average, shows a gradual increase through the month, though around the 25th there is often a brief dip before a warm end.

The average rainfall graphic reflects this, showing a three-day wetter spell after the 24th.

max max

 

may rain

 

 

Two April heatwaves compared

The stats are in and the average maxima for the past few days’ heatwave is 1C lower than the hot spell in 2011: a positive anomaly of 10.6C over six days.

Screen Shot 2018-04-23 at 13.34.29Screen Shot 2018-04-23 at 13.34.21

Although this year’s spell pipped the previous April high temp by 0.2C, the 2011 spell saw slightly higher temperatures and were recorded in a month that finished 3.3C above average – the average for this April is likely to finish only 2C above average.

April 2011 also saw just 3.3mm of rain recorded. The rainfall so far this month is already at 36.7mm, with more likely before the end of the month.

The spell in 2011 saw 74 hours of sunshine in total while this spell only saw 58 hours.

In terms of this summer it is quite possible that we won’t see a week with higher maximum anomalies or more sunshine than we saw across the southeast this week. To give you any idea of just how anon. warm last week was here is what the equivalent temperatures would be at the end of July, on average the warmest time of the year.

25th 29.8
26th 35.4
27th 39.2 (102.6F)
28th 37.7
29th 32.1
30th 33.3

* The Met Office definition of a heatwave (the same as the WMO) states:  “When the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5 °C, the normal period being 1961-1990”.

 

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The large anomalies of the past few days can be seen on this thermo trace

London’s April extremes since 1959

April showers bring spring flowers… so the saying goes though a look at local east London stats shows that eight of the last 11 Aprils have been drier than average, some remarkably so.

I’ve put together a few top 10s of stats for Wanstead, St James’s Park and Heathrow for the month of April.

Probably most notable from the below values is the top 5 maxima, made up during a warm spell in 2011.

Frosts can be common and are often sharp, playing havoc with budding plants

Snow can fall in April – a good few inches fell early in the month in 2008 – though any accumulation is usually short lived.

Rain – the characteristic April showers – is usually most frequent at the end of the month.

 

wanstead april

april SJP

april hth

 

The chart slideshow below show the synoptic situation which brought a notable warm spell in the second half of April 2011.

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Some UK April values according to TORRO

Hottest: 16th 1949: 29.4C at Camden Square, London.
Coldest: 2nd 1917: -15C at Newton Rigg, Cumbria
Wettest: 22nd 1970: 182.1mm at Seathwaite, Cumbria

In terms of climatology April maxima, considering the 1981-2010 average, shows a gradual increase through the month, though around the 21st there is often a jump of 3-4C, the start of a warm spell before rain arrives at month’s end.

The average rainfall graphic reflects this, showing a three-day drier spell after the 20th.

april max

april rain

 

 

 

 

 

Winter 2017/18 forecast review

At the beginning of December the opening par for my forecast for winter read:

The mean temperature for winter 2017/18 is looking average overall with average precipitation. While that doesn’t sound exciting for anyone looking for colder weather and snow I think the figures mask frequent 3 or 4 day-long cold snaps from the Arctic interspersed with milder interludes from Atlantic incursions; typical characteristics of a pattern driven by the troposphere. For anything longer term we have to hope for a warming of the stratosphere, a sudden stratospheric warming over the Arctic, that downwells into the troposphere, reversing the general westerly circulation. We are overdue an ‘SSW’ event but, even if one were to happen, its effects wouldn’t be felt until much later in the winter.

Figures generated using QBO statistics in the run up to December were identical to the outcome of 5C. It is figures generated using ENSO statistics, however, that produced the best results considering December, January and February alone.

It would seem that the winter was most influenced by the ENSO variable up until February when the effects of the SSW were enough to overcome it?results

 

 

Winter 2017/18: 27th out of 72

A few years ago I devised a winter index to try to decipher how modern winters ranked against legendary seasons, such as 1947 and 1963.

With the media hyping conditions last week, which were severe in many parts of the country, it is very difficult for many to gauge just how conditions compare with previous winters.

My findings show that this winter so far stands 27th. It is possible that further snowfall that results in lying snow at 9am between now and April will boost the position higher though, given recent years, this would seem unlikely.

index

Last week’s cold spell, while containing some impressive statistics, is put into perspective when it is compared with other severe spells since 1960. A decent cold spell but no record breaker in the form of a 1962/63.

Perhaps it is the advent of social media, the plethora of constant updates of the latest feet-deep snowdrifts and instant tales of heroism in the face of icy adversity, that has made this cold spell seem far more severe than it actually was in the minds of many; February / March 2018 was the first truly social media-driven cold spell.

Winter 2017/18: average, cold start and end

The winter of 2017/18 will probably be remembered as much colder that it actually was – the exceptionally severe spell right at the end was only at its halfway point by the time the meteorological winter was over.

pathfinder
Like a scene from the Pathfinder movie

The mean temperature for the season finished 5C, that’s 0.5C below average and the coldest for five years.

Rainfall was above average: 180.8mm fell, that’s 124 per cent of average and the wettest for four years.

Sunshine was just over average: 174.4 hrs is 104 per cent over average and the sunniest for tree years.

As so often with winters at this latitude the average for three months makes it look a non-descript season – it is only when you look at the detail that compelling facts emerge.

The coldest day of the season occurred on the last day of February when the maximum failed to rise above -1C, the first ‘ice day’ for five years and the coldest day since 2010. It was also the seventh equal coldest February day in a local record going back to 1959.

perch
Perch pond, being deeper, took longer to ice over

The coldest night of the winter was in the early hours of the 28th when a low of -6.9C was recorded. The temperature would have been far lower were it not for a shower that moved in at 3am.

The warmest day of the winter occurred on December 30th with 14.2C recorded. The warmest night was on January 28th when the temperature fell to just 10.8C.
The wettest day of the winter occurred on January 2nd when 15.3mm was recorded.

Snow arrived at the start of winter and at the very end: seven days of snow falling and four days of snow lying over the three months is below average.

 

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The daily mean temp yo-yo’d throughout December, January and February

There were 30 air frosts during the three months, eight above the 1981-2010 average.

air frosts

There were 11,680 minutes of frost over the winter, less than last year, though 66 per cent of those were recorded in February. Considering the past 6 Februaries this year’s frost hours were 170 per cent greater than the next highest, February 2016!.

frost minutes

A full weather diary is available for the months of DecemberJanuary and February. To view full stats for each month follow this link:http://1drv.ms/1kiTuzv

Summary for period 01/12/2017 to 28/02/2018

Temperature (°C):
Mean (1 minute) 5.2
Mean (min+max) 5.0
Mean Minimum 2.0
Mean Maximum 8.0
Minimum -6.9 on 27/02/2018
Maximum 14.2 on 30/12/2017
Highest Minimum 10.8 on 28/01/2018
Lowest Maximum -1.0 on 28/02/2018
Air frosts 30

Rainfall (mm):
Total for period 182.2
Wettest day 15.3 on 02/01/2018
High rain rate 28.2 day 02/01/2018
Rain days 52
Dry days 38

Wind (mph):
Highest Gust 45.0 on 02/01/2018
Average Speed 3.7
Wind Run 8059.5 miles
Gale days 0

Pressure (mb):
Maximum 1036.4 on 22/12/2017
Minimum 970.3 on 10/12/2017

Days with snow falling 7
Days with snow lying at 0900 4

 

 

London’s March extremes since 1959

I’ve put together a few top 10s of stats for Wanstead, St James’s Park and Heathrow for the month of March.

The month, the first of the meteorological spring can offer really contrasting weather; perishing cold and very pleasant warmth are both very possible, as the values show.

Probably most notable in the list is the cold March of 1962 which was the coldest of the 20th century and 11th coldest in a local list going back to 1797. March 2013 was also very cold. Strong winds from deep depressions often feature as does the odd blizzard.

Marches in the 1960s also appear to often start very cold and end very warm; the term ‘In like a lion, out like a lamb’ being very appropriate.
•Though this blog only covers extremes back to 1959, thanks to Met Office digitised data, I’ve unearthed records prior to this. Both W.A.L Marshall’s A Century of London Weather (covering 1841 to 1941) and J. H. Brazell’s London Weather (covering 1841 to 1964) confirm the coldest March day as the 13th in 1845 when 25F (-3.9C) was recorded at

The coldest March minimum was 4/5 in 1909 with 9F (-12.8C) at Epsom. Greenwich and Hampstead recorded 14F (-10C)

march extreme

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Some national UK March values according to TORRO

Hottest: 25C Wakefield, West Yorks – 29th 1929
Coldest: -22.8C Logie Coldstone, Grampian – 14th 1958
Wettest: 164.3mm Glen Etive, Highland – 26th 1968

march av tmax

march Tmin

march av rain

 

January 2018: rather mild, wet, dull

January 2017 was a wet month. Just over 64mm of rain was recorded, 121 per cent of average, slightly less than last January.Screen Shot 2018-02-04 at 21.20.29

The monthly mean finished 6.4C, 1.2C above average and the mildest January for four years.

Some 44 hours of sunshine were recorded, 88 per cent of average, the dullest January for six years.

The most notable event was during the early hours of the 18th when the ‘storm with no name’ felled many mature trees across a swathe of England, including a large beech on Blake Hall Road that led to the closure of the road during morning rush hour.

Air frosts: 4. Ground frosts: 12. Snow falling: 1

 

Full stats for January here:http://1drv.ms/1rSfT7Y

Summary for January 2018
Temperature (°C):
Mean (1 minute)  6.5
Mean (min+max)   6.4
Mean Minimum     3.5
Mean Maximum     9.3
Minimum          -2.4 day 29
Maximum          13.5 day 28
Highest Minimum  10.8 day 28
Lowest Maximum   4.1 day 20
Air frosts       4
Rainfall (mm):
Total for month  64.4
Wettest day      15.3 day 02
High rain rate   28.2 day 02
Rain days        19
Dry days         12
Wind (mph):
Highest Gust     45.0 day 02
Average Speed    4.2
Wind Run         3124.8 miles
Gale days        1
Pressure (mb):
Maximum          1031.2 day 29
Minimum          986.4 day 02
Days with snow falling         1
Days with snow lying at 0900   0
Total hours of sunshine        44.1