Last updated: March 2, 2024
The weather in Rock Falls, United States, during September is characterized by an average temperature of 20°C (68°F). Highs can soar to 32°C (91°F), while lows may dip to 7°C (45°F). Typically, the humidity level in Rock Falls throughout September hovers around 80%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In September, Rock Falls averages 115 mm (4.5 inches) of rainfall, typically over the course of 10 rainy days. The month enjoys an average of 12 hours 25 minutes of daylight, with the sun shining for approximately 9 hours 18 minutes each day. Additionally, there is a 63% probability of sunny days during this period.
Precipitation
Rainy days
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Chance of sun
In September, the UV Index in Rock Falls reaches a maximum of 8, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, 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 | 7 | 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 | ||||||