May 2024 was the warmest May on record with an average temperature of 13.08 °C, according to the latest weather statement from Met Éireann.
This temperature was 2.53°C above the 1961-1990 long-term average (LTA) or 1.74 °C above the 1991-2020 LTA for May.
This is only the second time, that the May average temperature exceeded 13 °C. The previous warmest May was May 2008 with an average monthly temperature of 13.03 °C.
The coldest May remains May 1923 (102 years ago) with an average temperature of 8.67 °C.
May weather
According to Met Éireann, May 2024 was very mild but also quite dull overall.
Weak steering currents aloft brought a mixture of slow-moving areas of high and low pressure over the country in a mostly slack airflow.
Rainfall totals were mixed with a few active weather fronts and some intense thundery downpours giving higher totals in the south and parts of the midlands, while the east and north-west had a relatively dry month.
The month began with low pressure meandering close to, or over, Ireland bringing bands of rain or showers at times as a warm and moist airmass moved in from the east and became established over the country.
It was mostly dry between Saturday May 4 and Saturday May 11 as high pressure gradually built over Ireland, which culminated in two warm and sunny days on Friday 10 and Saturday 11.
Thunderstorms broke out in the east on Sunday, May 12 before widespread frontal rain crossed the country on Monday, May 13 as low pressure moved close to the south coast.
Met Éireann stated that most of the rain that fell between Tuesday, May 14 and Friday, May 24 was convective in nature and came in the form of thundery downpours.
Some places got a lot of rain in sort intense bursts, especially the south and parts of the midlands, while other places stayed mostly dry with sunny spells at times.
Further frontal rain crossed the country on Saturday, May 25 and Sunday May 26 as low pressure approached from the west.
The month finished showery as low pressure pulled away and high pressure built from the west.
Rainfall in May
The majority of monthly rainfall totals across the country were below their 1981-2010 LTA.
Percentage of monthly rainfall values ranged from 48% (monthly rainfall total of 32.4mm) at Ballyhaise, Co. Cavan to 151% (monthly rainfall total of 106.5mm) at Mount Dillon, Co. Roscommon.
Monthly rainfall totals ranged from 29.3mm (50% of its LTA) at Casement Aerodrome, Co. Dublin to 124.7mm (136% of its LTA) at Knock Airport, Co. Mayo.
The month’s wettest day was also recorded at Knock Airport, Co. Mayo with 34.9mm on Sunday, May 26 (its highest daily rainfall in May since 2005).
Rainfall percentage of 1981–2010 monthly average for May 2024 (provisional) (left). Total monthly rainfall (mm) for May 2024 (provisional).
Temperature
It was the warmest May on record at 13 synoptic stations including Phoenix Park, Co. Dublin and Malin Head, Co. Donegal which have record lengths of 125 years.
Three stations had their highest mean maximum temperature for May on record, while 14 stations had their highest mean minimum for May on record.
There were no air frosts reported for the third consecutive May.
All mean air temperatures across the country were above their LTA for the month, according to Met Éireann.