May 2021 - Cold and wet - Saved only by the Bank Holiday weekend

May 2021 can now just be a distant memory. After the sunshine and warmth of the late May Bank Holiday weekend, it might be harder to remember all that rain and cold weather. The climate charts paint quite a picture. They compare data against a 30-year average. Currently, the 1981-2010 dataset before we move to 1991-2020.

You can see the strong dark blue over much of the UK. Wales recorded its wettest May on record. The record dates back to 1862, with Wales seeing 245mm of rainfall. The previous record of 184mm was set in 1967.  It was also very wet for SW England, northern England towards Yorkshire and the NE and for eastern Scotland. Conversely, western Scotland was much drier than average. Some of these wet locations received more than double their average rainfall amounts.

The Jetstream stayed away to the south allowing numerous low pressures to head towards the UK< bringing cloud and rain and later in May, strong winds. The UK was also stuck in colder air, often with a flow from the north. With strong sunshine at this time of year, there would be decent convection and thunderstorms developing. So, for specific locations, there were some high rainfall totals in the downpours along with hail and lightning.

It was cold by night with late-season frosts. Gardeners, growers and farmers were glad to see the rain after the drier weather earlier in spring, but the late cold caused other problems. If it hadn’t been for the warmth during the late May Bank Holiday weekend, May 2021 temperatures would have recorded “historically low figures”.  Northern Ireland did manage the average amount of sunshine, but Wales, England and Scotland were all below average.

Deep low for the time of year 21st May

Looking at Meteorological spring, the months of March, April and May

The end of March threw up the warmest UK March day in 50 years when Kew gardens reached 24.5C on the 30th. The rest of spring didn’t touch that with much of April and May stumbling about in the teens. By Easter Monday (early April) there were snow showers in the cold northerly flow and the frosts just kept on coming.

April 2021 was cold, frosty with very little rain. It was also the sunniest on record for the UK.

Spring 2021 was cooler than average, particularly for SE England. April was dry and sunny, May wet with more cloud but both felt cold. Plodding through more of lockdown with further restrictions, it seemed we all watched the weather more and noted how it was, but maybe didn’t want to venture out. For those who continued to walk, ride or run each month this year the comparisons of dusty, dry earth in April to muddy, slippery pathways in May, was stark. There were thunderstorms and cold winds until the very end of May and the end of spring. Sunshine and warmth for a bank holiday (away from the sea fog in the North Sea). The top temperature for spring 2021 was 25.1C in the end, Monday 31st for Highland Scotland with Greater London not far behind at 24.8C, so both higher than the March Kew Gardens value.

Summer 2021 has got off to a flying start with more sunshine, more warmth and temperatures a notch higher for the beginning of June. The monthly forecast has been updated for the rest of June.