Last updated: March 2, 2024
The weather in Gretna, United States, during September is characterized by an average temperature of 27°C (80°F). Highs can soar to 33°C (91°F), while lows may dip to 20°C (68°F). Typically, the humidity level in Gretna throughout September hovers around 79%.
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Average temperature
Maximum temperature
Humidity
In September, Gretna averages 147 mm (5.8 inches) of rainfall, typically over the course of 15 rainy days. The month enjoys an average of 12 hours 17 minutes of daylight, with the sun shining for approximately 9 hours 18 minutes each day. Additionally, there is a 47% probability of sunny days during this period.
Precipitation
Rainy days
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Chance of sun
In September, the UV Index in Gretna reaches a maximum of 10, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 12:00 and 14:00, during which unprotected skin may burn in as little as 15 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 1 | 1 | 3 | 5 | 8 | 10 | 10 | 9 | 7 | 4 | 2 | 1 | 1 |
| Exposure | Low | Moderate | VeryHigh | High | Moderate | Low | |||||||
| Time to burn | 45 min | 30 min | 15 min | 25 min | 30 min | 45 min | |||||||