Measurements:
°C
°F
Grand Isle
88°F
NW 5 mph
Feels like: 100°F
Precip: 8%
World Resorts USA Grand Isle Weather

Grand Isle Sea Water Temperature

Current Sea Water Temperature:
+89.2°F
Maximum Sea Water Temperature in August: 96.2°F
Minimum Sea Water Temperature in August: 87.8°F
Average water temperature in August: 92.1°F

Sea Water Temperature for the Last 10 Days:

August 05 89.2°F July 31 91.0°F
August 04 88.2°F July 30 91.6°F
August 03 89.4°F July 29 89.4°F
August 02 89.0°F July 28 92.6°F
August 01 91.4°F July 27 92.4°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: 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 89.8 °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 +94
Chicago +82
Hawaii +82
Houston +102
Las Vegas +124
Los Angeles +92
Maui +78
Miami +92
Myrtle Beach +84
New York +84
San Diego +80
San Francisco +62
Santa Monica +80
Sarasota +92
Washington +88
24 Hours Weather Forecast
Grand Isle
Local time: 13:24
05 aug, wednesday
1500 90°F
N
11 mph
1800 86°F
NE
10 mph
2100 88°F
NE
9 mph
06 aug, thursday
0000 88°F
N
9 mph
0300 88°F
N
8 mph
0600 86°F
N
5 mph
0900 88°F
NW
4 mph
1200 88°F
NW
8 mph