According to the Meteorological Office, spring begins every year on March 1st and ends on May 31st. Let’s look back at 2020’s meteorological spring.
It was a record breaker: the sunniest spring in the UK since records began in 1929. There were 626 hours of bright sunshine, which exceeds the previous record set in 1948 by over 70 hours. In fact, spring 2020 was sunnier than most summers: only the summers of 1976, 1995, and 1989 were sunnier.
Despite the sunshine, 2020 was only the eighth warmest spring on record and the fifth driest. These are figures for the whole country; some counties in the north east of England and the east of Scotland recorded their driest spring since 1862.
The position of the polar jet stream is one of the main drivers behind the variability of our weather in the UK. The jet stream is a narrow band of fast moving air at high altitude, usually (but not always) travelling from west to east. It is the outcome of Earth’s rotation on its axis and the temperature of the atmosphere and it separates cold polar air to its north and the warmer air to its south.
In late winter, the jet stream was stuck to the south of the UK, resulting in the wettest February on record. In contrast however, during March, it moved and became anchored to the north of the UK, allowing high pressure and sunshine to dominate our spring.
Global heating is changing the way in which the jet stream moves. A spokesperson from the Royal Meteorological Society, said: “It’s unprecedented to see such a swing from one extreme to the other in such a short space of time. That’s what concerns me. We don’t see these things normally happening with our seasons.”
So … watering a new-planted hedge, during lockdown, to save it from a spring heat wave may become commonplace in whatever our future turns out to be.
Header picture: the polar jet stream over Canada taken by NASA