The coldest and wettest days of June

Looking out the window on a cold and miserable June afternoon yesterday reminded me of similar such days during the Seventies and Eighties.

But the mind plays tricks and I wondered if these kind of days were that common in the past.

To weed out the also-rans qualifying days had to be sunless with an anomaly that was at least 4C cooler than the daily average and rainfall of at least 12mm.

This gave the following list.

24hrd

So, in the last 60 years there have been only 12 days similar to June 10th 2019. That would give a probability of less than 1% (0.00743)

Looking elsewhere it would appear that there was much more rain to the north, south and west of Wanstead.

rain all

 

 

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The curse of June 13th

1 Jun 21 Jun 16 Jun 77

June can be a strange month weatherwise. Scorching temperatures as well as washout, cold weather, perhaps epitomised by the Queen’s Diamond Jubilee pageant on the river Thames in 2012, can feature prominently.

The month can also throw up some striking anomalies, none more so than the fact that the 13th is the only day in the month where the temperature has ever reached or exceeded 30C anywhere in the British Isles.

According to TORRO the highest daily maximum recorded in the UK is 28.3C at Earls Colne, Essex, in 1948; at Brixton, south London, in 1896 and Aboyne in 1994. Yet either side of this date has records comfortably above 31C, as the table below shows.

torro.PNG

The closest we’ve got locally to 30C in the last 60 years was in 1989 when 27C was recorded.

So why is the 13th ‘cursed’ with traditionally being the coolest day of the month? The best explaination perhaps is the fact that the date occurs more or less during the middle of the North-west European monsoon.

According to Philip Eden’s list of singularities the June monsoon can strike any time between the 1st and 21st but normally peaks on the 16th with a 77 per cent frequency.

As well as cool temperatures the phenomenon can also bring copious amounts of rain, as happened in 1903 when large parts of Redbridge were inundated following a 59-hour deluge that started on… the 13th.

Will we see a repeat this Thursday? Unlikely, though the general pattern is not that different to what led to events over a hundred years ago.

13th

 

 

May 2019: average but dry

May finished average though the final figure, like April, masked cool warm spells.

The mean temperature finished 13.2C that’s 0.1C above average and nearly 2C cooler than last May.

Only 28.3mm of precipitation were recorded, 55.3 per cent of the 1981-2010 average.

Some 175.8 hours of sunshine were recorded, that’s 96.8 per cent of average..

To view full stats follow this link:http://1drv.ms/1kiTuzv

may tmax.PNG
‘Feels like’ maxima.
may 2019 feels like.PNG
May 1981-2019 maximum anomalies
may since.PNG

 

The 12 month rolling rainfall total has fallen below 470mm for the first time since July 2017.

12 month.PNG

Summary for May 2019

Temperature (°C):
Mean (1 minute)  13.3
Mean (min+max)   13.2
Mean Minimum     8.1
Mean Maximum     18.4
Minimum          2.5 day 11
Maximum          25.3 day 23
Highest Minimum  16.0 day 25
Lowest Maximum   10.9 day 04
Air frosts       0
Rainfall (mm):
Total for month  28.3
Wettest day      7.3 day 07
High rain rate   52.3 day 26
Rain days        11
Dry days         20
Wind (mph):
Highest Gust     20.6 day 04
Average Speed    1.9
Wind Run         1637 miles
Gale days        0
Pressure (mb):
Maximum          1041.8 day 13
Minimum          991.6 day 08
Days with snow falling         0
Days with snow lying at 0900   0
Total hours of sunshine        0.0