Summer 2025 has provisionally become the warmest for Ireland since records began in 1900, according to Met Éireann.

The average temperature for summer 2025 stood at 16.19°, which is 1.94° above Ireland’s long-term average (LTA) and marginally warmer (0.08°) than the previous warmest summer of 1995.

Until 2025, average summer temperatures in Ireland ranged from 12.65° to 16.11°, with 1995 holding a 126-year record starting in 1900.

The data also shows that August 2025 was provisionally ranked the fourth warmest August on record.

Met Éireann climatologist, Paul Moore, noted that summer 2025 was not particularly sunny.

However, he added that dry soils from a warm and sunny spring, heat domes over mainland Europe, periods of high-pressure dominance and the high sea surface temperatures around Ireland kept temperatures over the last three months consistently above average, especially at night.

"It’s a close call with the previous record held by summer 1995, as summer 2025 average temperature surpasses 1995’s by only 0.08°, even taking into account the temperature drop observed on the last week of August.

"Ireland is experiencing the effects of climate change, and our climate projections show that our climate is going to become warmer.

"2025 has already seen the warmest spring on record and now summer 2025 is another example of the warming trend, making it the first year since 1933 with consecutive spring-summer records," he said.

Over the period 1961-2020, Ireland’s mean air temperature increased at a rate of 0.22° per decade.

Of the top 10 warmest summers, six of them have occurred since the 2000s (2025, 2006, 2018, 2023, 2013, and 2022).

The report notes that 1995 and 2025 are the only two summers, and seasons, to ever surpass an average temperature of 16° for Ireland.

Summer 2025 was very warm overall and hot at times as Ireland was on the northern edge of high-pressure systems or heat domes on numerous occasions throughout the three months of the summer.

These heat domes brought widespread heatwave conditions across areas of the UK and mainland Europe, while also bringing a few transient hot spells for Ireland.

A maximum air temperature of 31.1° was recorded at Mount Dillon, Co. Roscommon, becoming the highest temperature of the year so far at Met Eireann's 25 primary weather stations.