Ireland in September: where is it warmest?
In September, Dublin averages 17 °C by day.
All destinations in September, warmest first
Long-term averages for the month: daytime high, sea, sunshine and rainy days.
| Place | Score | Air | Sea | Sun | Rain days |
|---|---|---|---|---|---|
| Dublin | 60 | 17° | 15° | 4 h | 12 |
Ireland in September: quick answers
Ireland in September: where is it warmest?
The warmest places in September are Dublin (17 °C).
Ireland in September: where is the sea warmest?
The sea is warmest at Dublin (15 °C).
Ireland in September: where is the weather best?
The best holiday weather in September – warm, sunny and dry – is in Dublin.
Ireland month by month
Ireland: weather & best time to visit
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)