Ireland experienced the warmest May on record last month, with an average temperature of 13.08°C according to Met Éireann.

There was also a lack of sunshine throughout much of the month, with some weather stations recording the dullest May in a decade.

It was 2.53°C warmer than the 1961-1990 long term average, 1.74°C above the 1991-2020 average, and only the second time in 125 years of data that we have experienced an average temperature of above 13°C in May.

Kerry Goes from Dullest to Sunniest Region

Direct sunshine is not necessary for solar panels in Ireland to generate electricity, and they work even when the sun is covered by the clouds.

But sunshine does of course increase output and for those with an array of solar panels installed, the more sunny days the better.

Unfortunately for these households, the warm temperatures weren’t accompanied by an abundance of sunshine for the most part.

But after a very dull April in the south-west, with just 128.5 hours of sunshine recorded at Valentia Observatory in Co Kerry, May was kinder to those in the area wishing for a sunnier month.

Valentia’s weather station went from the dullest in April 2024 to the sunniest in May, recording 161.1 total hours of sunshine.

At the other end of the scale, Gurteen, Co Tipparary was the dullest location observed in May, with 121.8 sunshine hours.

Shannon Airport received 142.8 total hours – its dullest May since 2014 and 21% duller than its long term average.

And it was a similar picture at Casement Aerodrome in Co. Dublin, where it was 20% less sunny than average (148.6 hours) and also the dullest since 2014.

The highest number of sunshine hours recorded in a single day was 14.9 hours at two locations on separate days – Johnstown Castle in Co. Wexford on Sunday 19 May, and Cork Airport on May 20.

There was also a wide variation in the number of dull days recorded – days with less than 30 minutes of sunshine.

This ranged from just 3 days at both Johnstown Castle in Co Wexford and Valentia Observatory in Co Kerry, to 10 days at Gurteen, Co Tipperary.

The south and north midlands were the wettest areas in May, while it was relatively dry in the east and northwest of the country.

Monthly rainfall values ranged from 48% (32.4mm) at Ballyhaise in Co Cavan to 151% (106.5mm) in Co Roscommon at Mt Dillon.

Michael Malone


Michael Malone is Solar Energy Editor at Energy Efficiency Ireland. He is committed to highlighting the benefits of solar PV for people across the island of Ireland, and is eager to clear up some misconceptions which linger among the Irish public regarding solar energy.

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