Measurements:
°C
°F
Grand Isle
64°F
N 9 mph
Feels like: 64°F
Precip: 0%
World Resorts USA Grand Isle Weather

Grand Isle Sea Water Temperature

Current Sea Water Temperature:
+62.8°F
Maximum Sea Water Temperature in December: 75.2°F
Minimum Sea Water Temperature in December: 57.6°F
Average water temperature in December: 67.6°F

Sea Water Temperature for the Last 10 Days:

December 18 62.8°F December 13 64.0°F
December 17 62.6°F December 12 63.8°F
December 16 64.0°F December 11 65.0°F
December 15 65.4°F December 10 66.4°F
December 14 65.6°F December 09 68.0°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: 2025 2024 2023

The average sea surface temperature in August 2025 for Grand Isle was 92.2°F. The maximum and minimum values were 90.0°F and 94.6°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Grand Isle was 92.5°F. The maximum and minimum values were 90.2°F and 95.0°F respectively.

Sea Water Temperature in June

Select Year: 2025 2024 2023

The average sea surface temperature in June 2025 for Grand Isle was 90.3°F. The maximum and minimum values were 87.2°F and 93.4°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 89.8 °F
July 89.3 °F
June 87.5 °F
Warmest sea temperature:
August 92.2 °F
July 91.3 °F
June 88.9 °F
The most cold months:
January 59.5 °F
February 62.4 °F
December 64.4 °F
The most rainy months:
July 5 days
June 4 days
August 4 days
The most windy months:
January 13 mph
March 12 mph
April 12 mph

Grand Isle on the Weather Map

USA Resorts:
NAME
Chicago +44
Hawaii +76
Honolulu +76
Houston +64
Las Vegas +48
Los Angeles +54
Maui +70
Miami +74
Miami Beach +78
New York +30
San Diego +52
San Francisco +48
Sarasota +62
Tampa +62
Washington +28
24 Hours Weather Forecast
Grand Isle
Local time: 06:33
18 dec, thursday
0900 64°F
NE
9 mph
1200 64°F
N
11 mph
1500 64°F
NE
15 mph
1800 66°F
E
13 mph
2100 66°F
E
12 mph
19 dec, friday
0000 66°F
E
11 mph
0300 66°F
SE
16 mph
0600 66°F
S
17 mph