Measurements:
°C
°F
Grand Isle
86°F
S 8 mph
Feels like: 94°F
Precip: 31%
World Resorts USA Grand Isle Weather

Grand Isle Sea Water Temperature

Current Sea Water Temperature:
+92.2°F
Maximum Sea Water Temperature in September: 93.2°F
Minimum Sea Water Temperature in September: 80.2°F
Average water temperature in September: 88.8°F

Sea Water Temperature for the Last 10 Days:

September 15 92.2°F September 10 91.2°F
September 14 91.6°F September 09 91.8°F
September 13 90.6°F September 08 92.6°F
September 12 90.4°F September 07 92.2°F
September 11 90.2°F September 06 91.8°F

When is the Warmest Sea for Grand Isle?

According to our data for the last three years for Grand Isle the highest average sea water temperature was in August, July and June.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2026 2025 2024

The average sea surface temperature in August 2026 for Grand Isle was 91.9°F. The maximum and minimum values were 88.2°F and 95.2°F respectively.

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Grand Isle was 91.5°F. The maximum and minimum values were 89.0°F and 94.0°F respectively.

Sea Water Temperature in June

Select Year: 2026 2025 2024

The average sea surface temperature in June 2026 for Grand Isle was 89.4°F. The maximum and minimum values were 85.6°F and 93.0°F respectively.

Best Time to Visit Grand Isle
The most sunny months:
October 18 days
September 15 days
November 14 days
The most warm months:
August 89.7 °F
July 89.3 °F
June 87.5 °F
Warmest sea temperature:
August 92.2 °F
July 91.3 °F
June 89.0 °F
The most cold months:
January 59.3 °F
February 62.0 °F
December 63.8 °F
The most rainy months:
August 4 days
July 4 days
September 4 days
The most windy months:
January 13 mph
April 13 mph
March 12 mph

Grand Isle on the Weather Map

USA Resorts:
NAME
Boston +62
Chicago +66
Hawaii +80
Las Vegas +80
Los Angeles +72
Maui +66
Miami +88
Myrtle Beach +78
New York +66
Panama City Beach +90
San Diego +70
San Francisco +60
Santa Monica +72
Sarasota +86
Washington +66
24 Hours Weather Forecast
Grand Isle
Local time: 07:58
15 sep, tuesday
0900 86°F
S
8 mph
1200 88°F
W
4 mph
1500 90°F
NW
10 mph
1800 90°F
NW
14 mph
2100 90°F
NW
9 mph
16 sep, wednesday
0000 88°F
W
9 mph
0300 88°F
W
9 mph
0600 88°F
W
14 mph