Last updated: March 2, 2024
The weather in O'Fallon, United States, during August is characterized by an average temperature of 24°C (76°F). Highs can soar to 34°C (94°F), while lows may dip to 15°C (59°F). Typically, the humidity level in O'Fallon throughout August hovers around 80%.
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Average temperature
Maximum temperature
Humidity
In August, O'Fallon averages 139 mm (5.5 inches) of rainfall, typically over the course of 12 rainy days. The month enjoys an average of 13 hours 35 minutes of daylight, with the sun shining for approximately 10 hours 35 minutes each day. Additionally, there is a 49% probability of sunny days during this period.
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Chance of sun
In August, the UV Index in O'Fallon 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 | 7 | 9 | 9 | 9 | 7 | 5 | 3 | 2 | 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 | ||||||