Hamilton Weather in September

The climate in Hamilton during September can be summarized as mild and dry.

September is in the fall / autumn in Hamilton and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 22°C (71°F), whilst at night 3°C (38°F) is normal.

On average September is the 4th wettest month of the year in Hamilton with around 29mm 1.2 inches of rain making it a dry time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.7 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 Hamilton in September 2025.