Last updated: March 2, 2024
The weather in Mount Vernon, United States, during September is characterized by an average temperature of 23°C (74°F). Highs can soar to 32°C (89°F), while lows may dip to 13°C (55°F). Typically, the humidity level in Mount Vernon throughout September hovers around 75%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In September, Mount Vernon averages 100 mm (3.9 inches) of rainfall, typically over the course of 10 rainy days. The month enjoys an average of 12 hours 22 minutes of daylight, with the sun shining for approximately 9 hours 48 minutes each day. Additionally, there is a 58% probability of sunny days during this period.
Precipitation
Rainy days
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Chance of sun
In September, the UV Index in Mount Vernon reaches a maximum of 8, 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 | 2 | 4 | 6 | 8 | 8 | 7 | 6 | 4 | 2 | 1 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | High | Moderate | Low | ||||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 25 min | 30 min | 45 min | ||||||