Weather in Mustang Island: September
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Average day temperature: | 87.0°F |
| Average night temperature: | 80.3°F | |
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Sea water temperature: | 85.3°F |
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Number of sunny days: | 14 days |
| Day length: | 11.9 - 12.7 hours | |
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Number of rainy days: | 2 days |
| Precipitation totals: | 1.0 in. | |
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forecast
| Mustang Island |
temperature
| Mustang Island |
Air temperature in September, °F
The highest day temperature during September of 2025 was 94°F. At the same time the lowest night temperature was 70°F. Daily and nightly averages during September were 89.3°F and 80.4°F.
Sea water temperature in Mustang Island in September, °F
The average sea water temperature in September of 2025 was 86.0°F. The highest and lowest sea temperatures during the month were 88.0°F and 84.2°F.
Mostly all days in September are sunny but cloudy days are also possible.
Precipitation total in September, in.
Precipitation total value in Mustang Island in September is 1.0 in. Other months of the year show relatively similar values.
The average wind speed value in September is 10.7 mph It makes September lest windy month of the year.
This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 8.2.
Best time for vacation in Mustang Island
Mustang Island on a weather map
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