Ketchikan Weather in September

The climate in Ketchikan during September can be summarized as mild and very wet.

September is in the fall / autumn in Ketchikan and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 14°C (57°F), whilst at night 7°C (44°F) is normal.

On average September is the 5th wettest month of the year in Ketchikan with around 279mm 11 inches of rain making it a very wet time to visit. This rainfall is typically spread over 18 days, although this may vary considerably.

On the flip side this corresponds to an average of 3.8 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Ketchikan in September 2025.