Despite the lack of sunny beach days, Ireland experienced its warmest May ever on record from the Met Éireann perspective, with average temperatures hitting 13.08 degrees. This was a significant increase, being 2.53 degrees above the 1961-1990 long-term average and 1.74 degrees higher than the 1991-2020 May average.
This occasion only marks the second time ever that May’s average temperature had crossed the 13-degree mark. The prior instance occurred in May 2008, where temperatures were slightly chillier, averaging at 13.03 degrees. Surprisingly, Ireland witnessed zero air frosts for three consecutive Mays, with 14 of Met Éireann’s synoptic weather stations recorded their highest mean minimum for May, while the chilliest May still continues to be in 1923, with the average temperature being 8.67 degrees.
Sunshine durations for the month were all beneath the long-term averages – Shannon Airport in Co Clare experienced their dullest May since 2014 at 79% of monthly sunshine values, followed closely at 80% by Casement Aerodrome in Co Dublin. Monthly sunshine hours varied between 121.8 hours at Gurteen, Co Tipperary and 161.1 at Valentia Observatory, Co Kerry. The highest daily sunshine hours – 14.9 – fell on Sunday 19th at Johnstown Castle, Co Wexford and on Monday 20th at Cork Airport.
Met Éireann’s climate log for May 2024 was described as “mostly calm, unexciting and occasionally stormy”. The forecasting agency pinned the pessimistic, stormy climate to a combination of stagnated high and low-pressure areas lingering over Ireland in mostly under-par airflow. The month remained relatively arid in the east and northwest regions. Despite a rainy start, the period between Saturday the 4th and Saturday the 11th saw a dry spell coincide with increasing pressure over Ireland, leading to a pair of warm and sunny days on Friday the 10th and Saturday the 11th.
The favourable weather didn’t persist, and on Sunday, the 12th of May, storms started brewing in the east. The next day saw widespread rain sweeping across the nation due to a frontal system and decreasing pressure nearing the southern coastline.
From the 14th to the 24th of May, the majority of the precipitation was convective, resulting in bouts of heavy, stormy rain. Further rainfall traversed the nation on Saturday the 25th and Sunday the 26th, courtesy of a low-pressure system making its way from the west.
The month concluded with intermittent showers as the low-pressure system retreated and a high-pressure system developed from the west. Overall, most places saw less than average rainfall with the south and north midlands bearing the brunt of the wetter conditions.