Stornoway Weather in September

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

September is in the fall / autumn in Stornoway and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 14°C (56°F), whilst at night 8°C (47°F) is normal.

On average September is the 5th wettest month of the year in Stornoway with around 134mm 5.3 inches of rain making it a wet time to visit. This rainfall is typically spread over 24 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 Stornoway in September 2025.