Weather in Dublin in September 2025
Average weather
Average temperature in Dublin in September
Going from a maximum of +81°F during the day to a minimum of +43°F during the night, the temperature in September averages around +66°F.
The average maximum temperature goes down 5% by the end of the month, compared with the beginning of the month, from +66°F to +64°F.
Is Dublin warm or cold in September?
Dublin is typically mild in September.
Maximum temperatures go down compared to the previous month from +66°F to +63°F. The minimum temperature also goes down from +55°F to +52°F.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how September is compared to other months in Dublin:
Water temperature in Dublin in September
Water in Dublin in September is Cold. It varies from +57°F to +60°F, with an average of +58°F. This is almost similar to the air temperature, which averages +63°F.
The water temperature in September is one of the warmest of the entire year:
Can you swim in Dublin in September?
Climate in Dublin in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +66°F | +63°F | +57°F | ||||
| Min. temperature | ||||||
| +37°F | +34°F | +25°F | ||||
| Max. temperature | ||||||
| +84°F | +81°F | +73°F | ||||
| Rainfall | ||||||
| 83 mm | 72 mm | 82 mm | ||||
| Wind | ||||||
| 4 m/s | 4 m/s | 5 m/s | ||||
| Avg. water temperature | ||||||
| +59°F | +58°F | +57°F | ||||
| Humidity | ||||||
| 80% | 81% | 83% | ||||
| Air pressure | ||||||
| 1013 HPa | 1013 HPa | 1010 HPa | ||||
| Sunny days | ||||||
| 1 | 1 | 1 | ||||
| Cloudy days | ||||||
| 9 | 11 | 11 | ||||
| Rainy days | ||||||
| 21 | 18 | 19 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. It’s getting colder in September. From +66°F in the day, the average maximum temperature lowers to +63°F. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 83 mm to 72 mm. Humidity rises from 80% to 81%. The average wind speed doesn’t change much during September, staying around 4 m/s. The amount of sunny days stay about the same, averaging 1 sunny days during the month.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 5 m/s getting up to 10 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Dublin is gradually increasing during September, going from 2 m/s to 4 m/s over the course of the month.
Rain
How was the weather last September in Dublin?
Climate Change Over the Years
The climate in Dublin in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1979 (+54°F) and the highest in 2023 (+58°F). The driest year was 1991 with only 627 mm of rainfall, and the wettest year was 2013 with 15853 mm.
FAQ
Is September a good time to visit Dublin?
Can you sunbathe in Dublin in September?
Can you swim in Dublin in September?
Is Dublin rainy in September?
Is it sunny in Dublin in September?
Other cities in Ireland
Monthly weather in Dublin
Source of the data
For this page, we’ve looked at the typical weather in Dublin, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.