Record-warm spring and May
Meteorological spring and May have just drawn to a close, and the data reveals that they have both been the warmest on record for the UK. This may come as a surprise to you, and I’ll discuss why perceptions haven’t matched reality in a moment. But first, the statistics.
Although spring and May were the warmest on record, they have been the 11th and 26th dullest, respectively, with sunshine for both 17% below average.
It’s also been a very wet spring – the sixth wettest on record – with rainfall 32% above average for the UK.
Perception versus reality
I’ve already mentioned the surprise that spring and May have been the warmest on record. So, what has made perceptions so different to what the data shows?
I think one significant factor is that despite being much warmer than average, it’s also been cloudier and wetter than average.
Being outside with a temperature of 20C on a cloudy, breezy day will feel very different to the same temperature on a sunny day. Even though the temperature is the same, the strong sun will make it feel warmer.
Nighttime temperatures have also been well above average, but how many of us would notice that if we are tucked up in bed? We are much more likely to notice and remember anomalously warm daytime temperatures – particularly extremes – rather than those which happen at night.
Additionally in May, the most anomalously warm areas – Scotland, N. Ireland and far north of England – are where a smaller proportion of the UK population live. Whilst other areas were warmer than average, it wasn’t to such a large degree, which may play a part in shaping how the warmth has been perceived.
Why so warm?
Weather patterns through spring and May have been conducive to often bringing consistently above average temperatures across the country – with the most anomalous warmth in May.
Secondly, climate change continues to play a significant role in increasing the chance of higher-than-average temperatures – both for the UK and globally. In fact, the past 11 months have been the warmest respective months on record globally – driven primarily by human-induced climate change, but also by the naturally occurring climate phenomenon El Nino.
The Atlantic Ocean continues to be astonishingly warm, with sea surface temperatures well above average for the time of year. Air destined for the UK has travelled over these warm waters, which inherently makes it warmer – and to a degree moister – when it arrives on our shores.
What does June and summer hold?
June is a notoriously tricky time to predict the weather far in advance. The jet stream and weather patterns move much more slowly and are weaker at this time of year. This significantly reduces predictability beyond a few weeks at most.
As for summer, other than looking at very broad general trends, it’s simply not possible to predict the weather in any useful detail like you see in a five-day forecast.
So, the ’50 days of rain this summer’ stories you may have seen published by some outlets recently are nonsense. No one knows such precise details so far in advance.
Anyway, as useful as it would be to know what the weather will do so far ahead, it would surely take the excitement out of our nation’s favourite topic of conversation. And who wants that to happen? I certainly don’t!
