The temperatures in Keflavik in September are quite cold with temperatures between 8°C and 10°C, warm clothes are a must.
You can expect rain for roughly half of the month of September in Keflavik. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Keflavik in September 2025.
If you’re planning to visit Keflavik in the near future, we highly recommend that you review the 14 day weather forecast for Keflavik before you arrive.
Temperatures
10° / 8°
Rainy Days
13
Snowy Days
0
Dry Days
17
Rainfall
204
mm
Sun Hours
6.6
Hrs
