The climate in Grand Isle during September can be summarized as hot, humid and wet.
September is in the fall / autumn in Grand Isle and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a steamy 30°C (87°F), whilst at night 22°C (71°F) is normal.
|Daytime temperature||30.4°C 86.7°F|
|Nightly temperature||21.8°C 71.2°F|
|Average temperature||26.1°C 78.9°F|
|Daily sunshine||8.1 hrs|
|Avg rainfall||165 mm 6.5 ins|
|Rainy days||10 days|
|Sea temperature||28.6°C 83.4°F|
|Windspeed||11.5kph 7 mph|
On average September is the 3rd wettest month of the year in Grand Isle with around 165mm 6.5 inches of rain making it a wet time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.
On the flip side this corresponds to an average of 8.1 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 Grand Isle in September 2022.
|Hottest month:||July||32.1°C 89.8°F|
|Driest month:||October||82mm 3.2ins|
|Coldest month:||January||16.3°C 61.3°F|
|Wettest month:||August||169mm 6.7ins|