Tag Archives: London weather extremes

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

 

 

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