The temperatures in Killarney in September are quite cold with temperatures between 8°C and 16°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Killarney during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Killarney in September 2025.
If you’re planning to visit Killarney in the near future, we highly recommend that you review the 14 day weather forecast for Killarney before you arrive.
Temperatures
16° / 8°
Rainy Days
6
Snowy Days
0
Dry Days
24
Rainfall
87
mm
Sun Hours
5.9
Hrs
