Climate change was directly responsible for some of the weather extremes last year, Met Éireann has said.
Last year was the second warmest year on record, surpassed only by 2023.
The average temperature was 11.14 degrees. This was 1.59 degrees above the 1961-1990 long-term average and almost a degree warmer than even the revised long-term averages from 1991 to 2020.
The highest wind speed ever recorded in Ireland occurred during Storm Éowyn last January when a gust of 184km/h and a 10-minute mean wind speed of 142km/h was recorded at Mace Head on January 24th.
Climatologist Paul Moore said climate change was resulting in more extreme weather events such as Storm Éowyn.
“Climate change adds extra energy to storms. With this extra energy, storms can be bigger and stronger and more devastating,” he said.
There were four named storms last year: Éowyn in January, Floris in August, Amy in October and Bram in December.
There was a marine heatwave in April and May, with Atlantic temperatures of 2-4 degrees warmer than average in offshore areas.
This contributed to the spring and summer of 2025 being the warmest seasons on record, even though there was no prolonged period of hot weather.
Dry soils from the warmest spring on record allowed heat to linger for longer, a marine heatwave pushed warm air up more consistently over Ireland and heat domes to the south of Europe occasionally extended as far as Ireland.
Another critical factor was warmer nights, with several long-standing stations having their highest number of warm nights on record.
The effects of climate change have become more pronounced in this decade, with four of the five warmest years on record occurring consecutively.
All have happened since 2022, with 2024 tying 2007 for the fourth warmest on record. The records go back to 1900.
Mr Moore said the effects of climate change on Ireland have been ongoing for a couple of decades, but the impact has been more “stark” in recent years.
“You can see clearly now the warming trend, as was expected. We knew it would lead to more extreme weather events. It’s clear and obvious.”
All of Met Éireann’s 25 official weather stations had above average temperatures for the year.
The highest temperature of the year for Met Éireann’s synoptic station was 31.1 degrees at Mount Dillon, Co Roscommon, on July 12th, though a station at Connemara National Park recorded 32.2 degrees on July 13th.
The lowest temperature of the year was minus 7.6 at Athenry, Co Galway on January 9th.
Rainfall for the year was 104 per cent of the 1991-2020 long-term average. There were long periods of drought in the spring with Casement Aerodrome seeing no rain between March 28th and April 14th.
May was another very dry month, but June and July were wetter than normal and last autumn was the fourth-wettest on record.