Hot air from the continent brought storms over Mid Sussex

Lightning last month - Photo by Stephen Munt
Lightning last month - Photo by Stephen Munt

A monthly column from the Middy’s meteorologist

The month made a cool, wet start on Tuesday/Wednesday 1st and 2nd with the min down to 34F (1.0C), which was the coldest night of the month, while 11.6mm of rain fell on the 2nd.

High pressure over Scandinavia brought in an easterly wind from the 4th giving heat wave conditions until the 9th. The max was 68F (20C) or more every day, reaching

81F on the 6th and 82F (28C) on the 7th. This was 22F above average, making it the warmest early May Bank Holiday since 1978. It was also outstandingly sunny with 70 hours of sunshine during this period.

From the 3rd to 23rd, it was mostly dry with significant rain only on the 12th (7mm). This was also one of the two sunless days in the month, and the max of 56F (13.4C) made it the coldest day of the month. However, from the 10th to 24th, max were generally above average, reaching 77F on the 15th and 76F on the 22nd.

From the 18th, warm, humid air over the Continent led to thunderstorms becoming a feature of the weather with some spectacular displays of lightning. In the south of Mid-Sussex, the wettest day was on the 29th with nearly an inch and a half of rain (42.5mm). This just beat 42.3mm on the 20th in 2004 to be the wettest day in May since 1950.

In the easterly wind, heat wave conditions returned from the 25th to 29th, with a max of 83F (28.3C) on the 28th, making it the second warmest day in May since 1950.

One of the most severe storms occurred in Haywards Heath on the 31st with over an inch of rain (32.5mm) in about an hour.

It was a notably warm and sunny month mainly due to the warm days, with the max reaching 77F to 83F on eight of the days. Nights were on the cool side until the 23rd but a run of very warm nights in the last week of the month brought the mean min up to 1.6F above average. This helped the mean temperature to be the fourth highest in May after 2008, 1992 and 1998.

Sunshine totals were not so high in the second half of the month and the total of 259 hours made it the sixth sunniest May since 1950.

From the 3rd to 23rd, it was mostly dry with a total of 10mm. However, the wet end to the month brought the rainfall total close to three and a half inches (86mm) but there have been many wetter Mays.