23.09
wed
wed
Day
86°F
W 5 mph
Precip.
4%
4%
Night
84°F
W 6 mph
Precip.
7%
7%
24.09
thu
thu
Day
86°F
W 6 mph
Precip.
14%
14%
Night
82°F
W 14 mph
Precip.
22%
22%
25.09
fri
fri
Day
82°F
W 14 mph
Precip.
4%
4%
Night
81°F
NW 14 mph
Precip.
15%
15%
26.09
sat
sat
Day
81°F
NW 6 mph
Precip.
14%
14%
Night
81°F
NW 8 mph
Precip.
14%
14%
27.09
sun
sun
Day
79°F
W 7 mph
Precip.
16%
16%
Night
81°F
NW 11 mph
Precip.
4%
4%
28.09
mon
mon
Day
81°F
NW 11 mph
Precip.
15%
15%
Night
82°F
NW 14 mph
Precip.
4%
4%
29.09
tue
tue
Day
82°F
NW 9 mph
Precip.
36%
36%
Night
82°F
N 16 mph
Precip.
41%
41%
sea water
temperature
temperature
| Grand Isle |
monthly
weather
weather
| Grand Isle |
current
weather
weather
| Grand Isle |
14 days
forecast
forecast
| Grand Isle |
Sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 86.9°F. The highest and lowest sea temperatures during the month were 88.3°F and 85.5°F.
Sea water temperature in October, °F
Show year:
2025
2024
2023
The average sea water temperature in October of 2025 was 80.1°F. The highest and lowest sea temperatures during the month were 84.7°F and 76.5°F.
Air temperature in Grand Isle, °F
Precipitation total in Grand Isle, in.
* Charts above show average data for the last 3 years.
Best time for vacation in Grand Isle
Grand Isle on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Grand Isle
Local time: 01:01
September 23, wednesday
0300
84°F
W
4 mph
4 mph
0600
82°F
S
10 mph
10 mph
0900
82°F
SW
9 mph
9 mph
1200
86°F
W
5 mph
5 mph
1500
88°F
W
14 mph
14 mph
1800
86°F
W
12 mph
12 mph
2100
84°F
W
7 mph
7 mph
September 24, thursday
0000
84°F
W
6 mph
6 mph
