That was the second-hottest September on record

THIS YEAR SAW the second-hottest September on record, with the average temperature being 15.22 degrees.

It ranks just behind 2021’s average of 15.27 degrees.

Last month, temperatures were 1.62 degrees above the recent 1991 to 2020 average and nearly 2 degrees warmer than September last year.

Met Éireann says that six of the 10 warmest Septembers on record have occurred since 2001, while none of the 10 coolest have occurred during that period.

“The fact that it was also quite wet and cloudy this September shows that the continued background warming, due to human-causing climate change, is the overriding factor behind this continued warming trend,” a spokesperson said.

Mace Head, Co Galway reported the lowest temperature, 11.3 degrees. This is the highest overall monthly minimum temperature for September at any synoptic station on record.

Advertisement

September 2026 was also wetter than average, recording 116.8 mm of rainfall, or 117% of the 1991 to 2020 average.

Many counties were put under rain warnings, particularly towards the end of the month, and thousands of homes lost power.

It’s provisionally been ranked the 38th wettest September on record. It was still drier than September 2025.

The number of wet days ranged from 12 days at Oak Park, Co Carlow, to 24 days at both Newport, Co Mayo, and Belmullet, Co Mayo.

There has been consistent extreme weather this year. This summer was the hottest one Ireland has seen across 127 years of weather records.

In contrast, looking at Ireland’s 10 coolest summers on record, none of them occurred in the last 25 years.

The World Meteorological Organisation said last month that global temperatures are on track to rise above the 1.5 degree ‘safe’ threshold set by the 2015 Paris Agreement – but it’s still not too late to prevent the climate crisis from escalating to absolute worst-case scenarios, if countries seriously get their act together to limit emissions.

Sign Up
The Journal's climate change newsletter Follow the biggest news story of our times. Sign up for our monthly climate newsletter

Sign up
You are now signed up