May proved to be much warmer, drier and brighter than normal with some weather stations recording their sunniest months since records began and average temperatures climbing significantly higher than historical norms, provisional figures from Met Éireann suggest.
Temperatures across Ireland in May were the sixth highest on record with the average of 12.54 degrees exceeding the 20th century norm by almost two degrees.
The data is in line with a trend of consistent May warming with the top seven highest average temperatures for the month having been recorded since 2008.
Blocking high pressure, positioned mostly to the north of Ireland, dominated for the first three weeks with Atlantic low pressure breaking through in the final week.
The abundant sunshine and slack easterly airflow intensified the marine heatwave off the south and west coasts that had been building through April.
May was 1.85 degrees above the 20th century average for the month and 1.21 degrees above the long-term average for the most recent climatological reference period of 1991-2020.
Mean temperatures were as much as 14.2 degrees at Shannon Airport, Co Clare – its warmest May on record – while the month’s highest temperature was reported at Newport, Co Mayo, on Tuesday, May 13th, which had a temperature of 24.8 degrees.
Average rainfall was measured at 56mm, representing 70 per cent of the month’s long-term average from 1991-2020.
That ranks the month as the 23rd driest May since 1941 and the fourth consecutive year to have below the long-term average rainfall for the month.
A total of 20 weather stations across the country recorded climatological dry spells – periods of 15 or more consecutive days with less than 1.0mm of rainfall – from the end of April into May.
[ Q&A: What should we do about multiple climate risks threatening Ireland? Opens in new window ]
Monthly rainfall values ranged from 31 per cent at Roches Point, Co Cork, to 104 per cent at Finner, Co Donegal.
Total hours of sunshine from all available locations were above the long-term average for 1991-2020, with two stations recording their highest ever monthly sunshine totals, and a couple of others their highest totals for May.
Record levels of sunshine were recorded at Shannon and Cork airports with Shannon basking in 288.9 hours of sun and Cork recording 290.4 hours. Johnstown Castle in Wexford had 298.8 hours of sun while Gurteen in Co Tipperary recorded 267.2 hours – their sunniest Mays on record. Elsewhere, Valentia Observatory in Co Kerry had its sunniest May since May 1961.
