Summer 2017 was a season of two halves, the mean temperature of 18.5C (1.3C above average) made it the tenth warmest summer since 1797.
Though it was warm overall it was also wet. Nearly 234mm of rain were collected, 159 per cent of average, making it the wettest summer since 1987.
Just under 535 hours of sun were recorded, 94 per cent of average and the sunniest summer for three years.
The final summer month proved to be a disappointment for anyone wanting a return of the heat in June.
The mean temperature finished 17.4C, 0.8C below average and the coolest August for three years.
Some 70.2mm of rainfall was recorded, 140% of the 1981-2010 average. Just over 170 hours of sunshine were recorded, 88 per cent of average.
To view full stats follow this link:http://1drv.ms/1kiTuzv
The 8th and 9th of August 2017 has produced probably the most miserable weather of this summer.
A rainfall event that began just after 8am on the 9th deposited nearly 36mm of rain in the Wanstead area over 14 hours.
The 09-09 total of 33.7mm made it the fourth greatest daily August rainfall since 1960.
The heaviest rain fell in a fairly narrow band, as shown by the official 24hr totals on ogimet.com. The low pressure system also produced a lot of rain for the east coast in the previous 24hrs with Bridlington recording over 56mm.
The rain brings the summer total to 207.7mm, just 0.6mm short of the amount recorded in 1997. Though it has been wet it is still a long way short of the wettest summer on record: some 391mm were recorded here in 1903.
In terms of temperature it has been a chilly start to August; the mean temp currently stands 1.2C below the whole month average. Considering CET it has been the coldest start to the month for 30 years.
July 2017 was the wettest since 1960. Some 92.3mm of rain were recorded which is 212 per cent of the 1981-2010 average.
Although the opening third of the month saw a continuation of the June heatwave temperatures gradually returned to normal values to leave the mean for the month at 19.2C, that’s 0.7C above average.
With all the rain sunshine totals were down. Some 167 hours were recorded, that’s 87% of average.
Though the rainfall total was impressive it is well short of the record of 164.2mm set in 1834, and is only 35th in the list going back to 1797.
Summary for July 2017
Temperature (°C):
Mean (1 minute) 18.9
Mean (min+max) 19.2
Mean Minimum 14.7
Mean Maximum 23.7
Minimum 9.4 day 12
Maximum 30.5 day 07
Highest Minimum 18.3 day 06
Lowest Maximum 19.0 day 24
Air frosts 0
Rainfall (mm):
Total for month 92.3
Wettest day 30.8 day 11
High rain rate 56.4 day 29
Rain days 10
Dry days 21
Wind (mph):
Highest Gust 17.4 day 27
Average Speed 2.9
Wind Run 2163.5 miles
Gale days 0
Pressure (mb):
Maximum 1024.2 day 16
Minimum 996.8 day 31
Total hours of sunshine 167
In terms of the rest of the summer a look at the ECMWF control run out to 10 days suggests an unsettled start to August with the jetstream centred right over the top of the UK. Things may improve as the Azores high attempts to exert more influence – so perhaps more in the way of sunshine than of late. In terms of heatwaves it is impossible to tell at this range.
1st: Cloudy but with sunny spells developing, these growing longer in length by evening.
2nd: Sunny with just a few light cumulus.
3rd: Sunny start though with plenty of cloud around, this tending to thicken after lunch with odd spot of rain.
4th: Sunny and very warm early then tended to cloud over before sun returned in the late afternoon and evening. Some very unstable low to mid level cloud.
5th: Sunny with just a few cirro-cumulus. Feeling very warm with cloud bubbling up in the evening, however forecast storms failed to materialise.
6th: Sunny with cirrus and dotted cumulus. This tended to thicken late morning though sun stayed out and became hot and humid.
7th: Sunny with lots of high-level cirrus and cumulus most of the day.
8th: Bright but mostly cloudy start, the cloud tending to vary through the day. Sunny after 4pm. Warm overnight.
9th: Bright but mostly cloudy start, the cloud tending to break and vary through the day.
10th: A mostly sunny morning and lunchtime until 2pm when it clouded over.
11th: Cloudy with some bright breaks at first. Cloud thickening with rain by noon, this falling sporadically before getting going after 5pm and stopping by 3am.
12th: Cloudy, damp and close start.
13th: Sunny with variable cloud until noon when there were just bright spells.
14th: Cloudy but with a few breaks around mid morning. Turning cloudy again before sunny spells in the evening.
15th: Cloudy with some sporadic rain as warm front blew through and close. Very limited brightness.
16th: Cloudy with some bright spells. Feeling warm and humid.
17th:Sunny with just a few cirrus drifting around. Feeling hot, cloud thickened from the west in the late afternoon.
18th: Sunny with variable cirrus and cirro cumulus through the day. Feeling very warm. Storms began building with supercell to west of London and over Chilterns.
19th: Cloudy, dull start and very humid with heavy mist – the cloud tended to lift to give sunny spells in the afternoon.
20th: Drizzle after shower before obs time, then showers through to 1pm.
21st: Cloudy start but with sunny spells developing. Clouded over in evening with intermittent heavy rain at 11pm and through the early hours.
22nd: Cloudy but with sunny intervals developing around noon. Heavy showers developing with thunder at 2.30pm and 3.07pm.
23rd: Bright with variable cloud
24th: Cloudy with light, showery rain from northerly airstream that originated in the Med.
25th: Cloudy with light rain just after obs time.
26th: Cloudy with occasionally rain. Feeling warm and a late clearance. Breezy and chilly overnight.
27th: Cloudy but bright and sunny spells developing. A very heavy shower at 1pm.
28th: Bright start but clouding over.
29th: Sunny start with cloud increasing after noon to leave overcast before patchy rain moved in. This falling more heavily at 5pm before clearing to further showers. More rain overnight before a strong squall arrived at 2.45am and lasted an hour with further bursts of rain through the night – two claps of thunder and lightening during squall.
30th: Sunny with variable cloud through the day. Very warm in the sunshine
31st: Sunny with variable cloud throughout the day.
I’ve seen this phrase uttered more than once over the past couple of days thanks to high temperatures and humidity. But ask anyone to define a hot day and you’ll get a different answer every time.
Growing up in the 1970s / 80s redtop newspapers would use the phrase once the mercury was nudging 80F (26.7C). But to ‘scorch’ you need sunshine, preferably at least 10 hours of it. Considering statistics from the Heathrow airport climate station in west London there have been 463 scorchers since 1959, the most recent happening on July 5th with 29.5C recorded and 13.9 hours of sunshine. There have now been 9 scorchers this year, already matching the number that were recorded in 2014 and only 3 short of last year.
But even with last month’s heatwave this year has some way to go, however, to match the amount measured in 1976 and 1995: 31 days!
June 2017 has been a month of real contrasts. A thundery deluge on the 2nd was followed by conditions typically brought by the European monsoon.
Warm weather followed in the second week before a full-blown heatwave arrived bringing the hottest June spell since 1976.
The mean temperature for the month finished at 18.9C, that’s 2.8C above average. It was the second warmest June in a local record going back to 1797. Though it was only 0.4C cooler than 1976 it was also much wetter than that very dry month.
Though it appeared a wet month, over two-thirds of the recorded rain fell in two episodes.
Sunshine for the month was 202.3hrs, 114% of average.
In terms of the rest of the summer you would be forgiven for thinking that we have already had more than our fair share of good weather. One way of looking at it is to count the number of days the mercury rises above 25C with 10 hrs of sunshine. Since May that has happened on 13 occasions – far higher than anything in the past four years.
It will be interesting to see if July and August, normally the months where we get most of our summery weather are as good as June.
1st: Sunny with scattered cumulus through the morning, the cloud thicker during the day.
2nd: Cloudy start though brightening up with long sunny spells. Cloud bubbled up and a heavy thunderstorm moved in at 3.15pm and lasted an hour. Sunny again by 6pm.
3rd: Bright start with decreasing cloud.
4th: Sunny start though cloud bubbling up late morning into early afternoon. Cloudy and breezy with a few spots of rain at dusk.
5th: Cloudy and very breezy start. Bright at times.
6th: Rain and very windy to start with gale force 9 in Channel. Rain lasted into the early afternoon before clearing to bright spells. Odd shower overnight but remained blustery with a few trees down. Flowering cherry fell at mum’s at 6.30pm.
7th: Sunny with long sunny spells. An area of rain after dark then overcast through the night.
8th: Cloudy and breezy, a shower at noon and some bright spells at 1pm.
9th: Sunny though breezy with lots of cloud. Spots of rain in the wind.
10th: Sunny and warm start with lots of sunshine. Very breezy.
11h: Sunny and feeling very humid but breezy. Alternating between very warm sunshine and cloud. Very brief few drops of rain at dusk then mostly cloudy night.
12th: Sunny periods throughout the day. Cloudier at times. Clear overnight with warm, sunny start.
13th: Sunny, clear start and feeling warm early.
14th: Sunny most of the day with odd cumulus. Very warm though turning a bit fresher overnight.
15th: Sunny morning though with more cloud than yesterday. A fresh breeze developing.
16th: Sunny with variable cloud. Warm.
17th: Sunny though lots of hazy cumulus.
18th: Sunny though much cloud amid the humidity. Felt airless with only limited breeze. Oppressive overnight.
19th: Sunny with cloud decreasing
20th: Bright start though cloud breaking at 11am to leave clear afternoon with just a couple of cumulus.
21st: Sunny and hot all day with patchy cirrus. Warmest June day since 1976 at Heathrow 33.9C. Warm overnight but more of a breeze. Sunny early.
22nd: Very brief rain shower at obs time then sunny intervals. Cooler but still humid. Very breezy overnight.
23rd: Long sunny spells with hazy cumulus. Although cooler still hot in the sunshine. Cooler overnight and breezy.
24th: Mostly cloudy though bright. A sharp shower in the evening.
25th: Bright though mostly cloudy. A couple of bursts of drizzle but then sunny spells late evening.
26th: Sunny with lots of cirrus, cirrocumlus and a fallstreak hole in the sky. Warm but low humidity.
27th Sunny start though sun becoming scarce. Patchy light rain at 10.30am and thunder then a heavy shower at 3.45pm. Rain in the evening that lasted into the early hours.
28th: Cloudy and very dull at times with very light drizzle. Humid.
29th: Cloudy though bright with some sunny intervals.
30th Sunny though with lots of cloud. Decreasing cloud in the afternoon and a pleasant evening.
Heatwave hype has been building over the past few days and, for once, the media has been justified in its coverage of the current spell.
Temperatures over the past few days have been enough for the Met Office to trigger its Heath-Health Watch whereby the mean temperature (an average of the maximum and minimum) for two consecutive days reaches 23.5C.
A couple of years ago I compiled a list of heatwaves for this area back to 1852 where the mean temperature reaches at least 23.5C three days running. This spell, the only other June heatwave (the other being 1976!), only just scrapes into the list.
Although it felt hot this spell, in terms of Premier League quality, was more Middlesbrough than Chelsea.
Forecasters say today is likely to be the hottest June day for 40 years though I’d be surprised if we exceed the 34.2C recorded on June 27th 2011. It would be the fifth day running that 30C has been reached in this area, enough to fulfil the World Meteorological Organisation’s (WMO) definition of a heatwave.
Whatever happens today the fact that the heat has been produced by a tropical maritime airmass is remarkable. With France and Spain recording some very high temperatures of late the same pattern in July and August could put more records at risk of being broken.
This week marks the 41st anniversary of the start of probably the finest British summer in history, but anyone hoping that yet another parallel with the 1970s is about to come true should take a look at the latest model runs.
Widespread heavy rain and gales across the UK have made the start of summer feel very unseasonal. But the conditions, which follow an extended period of mostly dry weather, are very typical for early June.
The ‘NW European monsoon’ is one of the most reliable ‘singularities’ on the annual weather calendar. Though it sounds very unscientific that the atmosphere can remember how it behaved on a certain date in previous years much statistical work over the past 170 years highlight tendencies for unusual weather at particular times of the year. These tendencies were first identified by the German climatologist, A.Schmauss, in 1938.
While the pattern isn’t set in stone statistics show that the probability of the euro monsoon occurring between June 1st and 21st is 77 per cent.
One of the most notable inclement spells of weather in June happened during the D-Day landings in 1944.
With the changes in ice at the North and South Poles, together with the massive positive temperature anomalies last winter, it would be thought logical that this would have some bearing on the general pattern this year. But polar ice is only one variable to consider when trying to predict the world’s climate.
The mean temperature for May 2017 of 14.7C was 1.6C above average; the warmest for six years and the 11th warmest in a local series going back to 1797.
Despite the first ten days of the month continuing the dry spell that has plagued London for months the total recorded finished above average: 62.5mm rainfall (122% of the 1981-2010), the wettest May for three years.
Though the month finished warm with some cracking sunny days the first two-thirds of the month were relatively dull: 157.1hrs of sunshine were recorded which is 86% of average, the dullest for 13 years.
I published my summer forecast on June 1st. It’s looking average.
Here follows the full weather diary for May. To view full stats follow this link:http://1drv.ms/1kiTuzv
1st: Cloudy all day with just a few bright intervals.
2nd: Sunny and clear morning, cloud bubbled up at noon. Cloud thickened with very light drizzle at 8pm.
3rd: Cloudy, dull with occasional very light drizzle.
4th: Cloudy and feeling chilly all day. Odd drizzle.
5th: Sunny start though cloud thickened quickly to leave an overcast though bright, breezy afternoon.
6th: Cloudy all day with a couple of bright spells.
7th: Cloudy and cool start, cloud decreasing after noon, eventually clearing to leave long sunny spells at 5pm.
8th: Cloudy and cool start – the cloud sticking all day and felt chilly.
9th: Cloudy and cool start, cloud decreased late afternoon but did not completely clear until 5am, saving area from frost. -2.8C in Benson!
10th: Sunny and mostly clear into the afternoon with patchy cirrus.
11th: Sunny and humid to start with much high-level cirrus. Breezy too. Showers overnight.
12th: Cloudy start, one or two light showers before a brief heavy one at 2pm. Sunny spells developed late afternoon.
13th: Cloudy start before cloud decreased to long sunny spells in afternoon. Cloudier overnight with showers between 7am and 8am.
14th: Sunny spells and breezy. Cloudier overnight with shower at 7am.
15th: Light rain and showers through the morning, clearing in the afternoon to sunny intervals.
16th: Bright start with cloud decreasing. Some very warm sunny spells – felt like summer for first time. Light rain in the evening though it didn’t start falling consistently until 2am with heaviest fall arriving at 4am.
17th: Bright start with plenty of sunny spells. Showery rain arrived at noon, turning more persistent at 4pm, clearing around 10pm.
18th: Bright start with lots of sunshine. Cloud began thickening at 1pm with bursts of light rain. Persistent rain arrived at 3.30pm and was still moderate to heavy at 10pm. Started petering out at midnight but then two further showers at 3am and 5am.
19th: Showery with longer spells of rain. This tended to clear to sunny spells. Thunder in the evening with a brief heavy shower at 6.23pm.
20th: Sunny, warm and breezy morning to 1pm.
21st: Sunny start with cumulus bubbling up. Sunny spells thereafter, growing longer as day wore on. Still 20C at 6pm during first Music in Wanstead Park. Overcast early but cloud started to break around 8am.
22nd: Sunny with decreasing cloud, clear by 1pm with just patchy cirrus.
23rd: Cloudy start with sunny spells mid morning, turning mostly cloudy again though.
24th: Bright start with variable cloud and sunny spells.
25th: Sunny with variable cloud at obs time, the cloud quickly clearing though a convection line could be seen in the west from Essex.
26th: Sunny and clear though breezy. Long sunny spells through the day. Feeling hot. Thunder and brief downpour between 8.30am and 9am.
27th: Sunny though only after front had cleared. Then alternating cloudy to sunny. More cloud late afternoon and not feeling as nice as forecast.
28th: Sunny start with variable cloud though the day. Rain in the evening before storm arrived at 1am, the rain turning heavier at 1.45am and lasting till just gone 3am.
29th: Cloudy start though soon turning brighter. Feeling humid with occasional very light rain.
30th: Cloudy but bright with the odd break. Feeling fresher
31st: Bright start with plenty of holes in the alto cumulus. Cloudier in the afternoon
It’s not often you experience what it’s like to be right under a cloudburst but June 2, 2017, provided a perfect example.
Some 31.2mm of rain fell in little over an hour accompanied by frequent thunder and lightning. Some flash flooding was reported and there was an 8C fall in temperature in 2 hours. The max rainfall rate was 108.4mm/hr at 3.49pm.
The rain started at 3.14pm
Elsewhere in London there were reports of ‘golf ball sized’ hail in Orpington. Here is a link to the pictures posted on ukweatherworld.co.uk https://1drv.ms/w/s!Au79-nZSg0ihlSXF5dTb08AQB74b
Tudor Hughes, of Warlingham, NE Surrey, said: “Heavy thunderstorm 1525Z.. Torrential rain and a short spell of large hail near the end. The stones were all spherical with a maximum diameter of 12 mm. Temp fell “vertically” from 22° to 17°. Just measured the rainfall – 12.7 mm, the bulk of which fell in about 7 mins. Rain now (1555 Z) ceased but plenty of Cb still around.”
Smartie, a contributor to the Google group Weather and Climate, explained the science behind the storm.
“The cold front was still to the west, these showers were in a prefrontal trough. South-east London was in the inflow region of the convergence zone and strong initial updraughts and unimpeded ingestion of air from the SE likely accounts for the hail. Storms north and north-east of London likely benefited from urban heat.”
Wanstead Meteo 
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