Saint Johns Weather in September

The climate in Saint Johns during September can be summarized as mild and reasonably dry.

September is in the fall / autumn in Saint Johns and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a comfortable 27°C (80°F), whilst at night 9°C (49°F) is normal.

On average September is the 3rd wettest month of the year in Saint Johns with around 31mm 1.2 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 6 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.7 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 Saint Johns in September 2025.