A WEEK of searing heat during the half-term holiday contributed to the breaking of long-standing records for Jersey’s warmest May, Jersey Met has confirmed.
Data released yesterday showed an average temperature of 16.5°C across the month – 2.7°C above the average May figure for the three decades ending in 2020 and 0.7°C above the previous record, set in May 2008.
The breaking of records was fuelled by last week’s heatwave, which saw temperatures in excess of 30°C for five consecutive days, including a record May high for the Island of 34.2°C and a so-called “tropical night” when the mercury did not fall below 22°C.
Figures were also published for the three-month season that ended on 1 June, showing that it was Jersey’s warmest-ever spring, with an average figure of 13.5°C being 0.8°C ahead of the previous record – set last year – and well clear of the 30-year average figure of 11.1°C.
Senior forecaster Matt Winter described the recent heatwave as “exceptionally unusual”, adding: “Some of the records were broken by big margins, including the record high for May and the overnight low.
“When you’ve got data going back 130 years, you would expect any new records to be perhaps a tenth of a degree or two higher, so to have the May and spring records broken by 0.7°C and 0.8°C is really quite something.”
Mr Winter noted that the effects of climate change were being seen in more intense periods of heat.
“With a weaker jet-stream, we are liable to see the sort of blocking high that we saw last week,” he said. “It acted as a bit of a ‘lid’, stopping the heat dissipating and causing the temperature to build up day after day.”
While May’s total rainfall was around 35% below average, and spring as a whole was the fourth-driest on record, June got off to a wet start, with 21.7 millimetres of rain falling at Maison St Louis in St Helier between sunset on Monday and sunrise yesterday.
