Weather in Grand Cayman: September
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Average day temperature: | 86.9°F |
| Average night temperature: | 83.6°F | |
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Sea water temperature: | 86.1°F |
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Number of sunny days: | 10 days |
| Day length: | 12.0 - 12.5 hours | |
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Number of rainy days: | 4 days |
| Precipitation totals: | 2.1 in. | |
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forecast
| Grand Cayman |
temperature
| Grand Cayman |
Air temperature in September, °F
The highest day temperature during September of 2025 was 90°F. At the same time the lowest night temperature was 83°F. Daily and nightly averages during September were 88.0°F and 84.4°F.
Sea water temperature in Grand Cayman in September, °F
The average sea water temperature in September of 2025 was 87.4°F. The highest and lowest sea temperatures during the month were 87.8°F and 86.9°F.
Mostly all days in September are partly cloudy but sunny or cloudy days are also possible.
Precipitation total in September, in.
Precipitation total value in Grand Cayman in September is 2.0 in. Other months of the year show relatively similar values.
The average wind speed value in September is 10.5 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: 7.5.
Best time for vacation in Grand Cayman
Grand Cayman on a weather map
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