According to the Met Office, the UK has just experienced the wettest June since records began in 1910. This actually is a slightly misleading statement, as the Met Office, on their own website, have records going back to 1766, which confirm that, in England and Wales, 1860 was the wettest year with 157.1mm compared to 151.2mm this year. (Figures for Scotland are shown separately, which show there have been seven wetter Junes since 1910).
As for UK temperatures, June has been the 19th coldest since 1910 and 0.35C colder than the 1971-2000 average.
It all seems an age ago since the Met Office issued their three month outlook for April-June, at the end of March. For anyone who has forgotten, it forecast:-
SUMMARY – PRECIPITATION: The forecast for average UK rainfall slightly favours drier than average conditions for April-May-June as a whole, and also slightly favours April being the driest of the 3 months.
And
SUMMARY – TEMPERATURE: The UK-average temperature forecast for spring (April-May-June) shows a range of possible outcomes that are warmer than the range observed between 1971 and 2000 (our standard climatological reference period), but quite similar to the last decade. For April the forecast also favours temperatures being warmer than the 1971-2000 reference period.
April, of course was as wet and cold as June has been, and although May was slightly warmer than average, it was also wetter. Taking the three months together, we get:-
Mean Temp Centigrade | Rainfall mm | |
April | 6.3 | 126.5 |
May | 10.5 | 66.8 |
June | 12.3 | 145.3 |
April-June Average | 9.7 | 112.9 |
1971-2000 Baseline | 9.9 | 69.5 |
Long Term Trends
Analysis of rainfall data for June back to 1766 highlights some interesting facts, as the two following graphs show.
There is naturally a lot of noise in the first graph, but the trend line indicates a drop in rainfall. It also shows just how big the inter-annual variability can be. (Well, this is England we are talking about!) The ten year running average, however, shows some significant changes occurring over the period.
1) Much wetter Junes seemed to be a regular occurrence at the start of the record and then again in the mid 19thC.
2) Both these interludes were followed by much drier times, particularly in the early 20thC.
3) Compared to the decadal variability apparent through most of the record, rainfall levels since about 1960 have been remarkably stable.
Could the trend in the last few years towards wetter Junes be marking a return to the volatility of the 18th and 19th centuries?
Meanwhile climate models used by the UK Government project a decrease in summer rainfall of up to 60% by 2080, but more on this later.