Ireland has recorded its second-hottest September since national records began in 1900, according to provisional Met Éireann data. The result adds to a year of exceptional warmth and provides another clear signal of the country’s changing climate.
Key facts from Ireland’s latest weather report
- September’s average temperature was 15.22°C.
- The warmest September remains 2021, at 15.27°C.
- The latest figure was 1.62°C above the 1991–2020 average.
- It was 2.29°C above the 1961–1990 average.
- Rainfall reached 116.8mm, or 117% of the modern average.
- The month was provisionally ranked the 38th wettest September on record.
Why this September was so warm
Met Éireann said September was dominated by a pattern that brought a mild, mobile Atlantic airflow across Ireland. Low pressure to the north and high pressure to the south helped maintain generally mild conditions, although the month also included frequent rain and showers.
The weather was not consistently sunny or dry. That combination of warmth, cloud and rainfall is significant because it shows that higher average temperatures can persist even when conditions do not feel like classic summer weather.
Met Éireann climatologist Paul Moore identified human-caused climate change as the overriding factor behind Ireland’s continuing warming trend. He also noted that Ireland had already experienced its third-warmest spring and hottest summer on record during the same year.
Latest Irish News: September joins a longer warming trend
The latest data fits a broader pattern in Ireland’s climate records. Six of the country’s 10 warmest Septembers have occurred since 2001, while none of the 10 coolest Septembers has occurred during that period.
September 2026 was only narrowly behind the record set in 2021. Its average temperature of 15.22°C was 0.05°C below that earlier mark, making it one of the closest approaches to a national monthly record in recent years.
These figures are provisional, meaning Met Éireann may update them as observations are checked and finalised. However, the central finding is already clear: September was exceptionally warm by both recent and historical standards.
Warm and wet conditions across Ireland
Rainfall was also above average. Ireland received an average of 116.8mm during September, equivalent to 117% of the 1991–2020 September average. The month was wetter than August but drier than September 2025.
The combination of elevated temperatures and above-average rainfall reflects the influence of Atlantic weather systems. It also underlines why Ireland weather cannot be assessed through temperature alone. Rainfall, sunshine, wind direction and the origin of air masses all shaped the month’s conditions.
Notable weather patterns during the month
- Warmest spells: September 2nd, 12th, 14th and 21st saw temperatures reach the mid-20s in some locations.
- Warm air: These days followed warm fronts that brought tropical maritime air from the south or southwest.
- Sunniest days: September 8th, 15th and 23rd were among the brightest days.
- Cooler air: Those sunnier periods followed cold fronts that introduced slightly cooler polar maritime air.
What the Met Éireann findings mean for Ireland
Climate records measure long-term patterns rather than individual experiences. Some parts of Ireland may have felt cooler or wetter than others on particular days, but national averages help identify broader changes that are difficult to see from day-to-day conditions.
The latest result matters for several areas of public life, including agriculture, water management, public health and infrastructure planning. Warmer seasons can affect growing conditions, while intense or persistent rainfall can place pressure on drainage systems, roads and local waterways.
For households, the report is also a reminder that Ireland’s weather is becoming more variable against a warmer baseline. A mild September does not predict the exact conditions of the coming winter, and Met Éireann’s monthly climate statement should not be treated as a seasonal forecast.
What happens next?
Met Éireann is expected to confirm the final September figures after the provisional observations have been reviewed. The completed record will show whether the ranking changes, although the current data places the month just behind September 2021.
Attention will now turn to October conditions and to whether the wider year continues to rank among Ireland’s warmest on record. Individual cold spells may still occur, but they will not erase the long-term pattern identified by the national forecaster.
Frequently asked questions
Was September 2026 Ireland’s hottest September?
No. It was provisionally the second-hottest September recorded in Ireland. September 2021 remains the warmest, with an average temperature of 15.27°C.
How warm was September 2026?
The national average temperature was 15.22°C. That was 1.62°C above the 1991–2020 average and 2.29°C above the 1961–1990 average.
Was September also unusually wet?
Yes. Average rainfall was 116.8mm, representing 117% of the 1991–2020 average. Met Éireann provisionally ranked it as the 38th wettest September on record.
Does a warm September prove climate change?
One month alone does not establish a climate trend. However, the repeated appearance of exceptionally warm months in recent decades is consistent with the long-term warming linked to human-caused climate change.
Conclusion
This Breaking News update confirms that Ireland has experienced its second-hottest September on record, despite a month that was also cloudy and wetter than average. Met Éireann’s findings place the latest result within a sustained pattern of warming, with six of Ireland’s 10 warmest Septembers occurring since 2001. The key takeaway is clear: Ireland’s climate baseline is rising, and the effects will continue to shape weather, planning and daily life across the country.
