Last updated: March 2, 2024
The weather in Alpena, United States, during September is characterized by an average temperature of 16°C (61°F). Highs can soar to 27°C (81°F), while lows may dip to 6°C (44°F). Typically, the humidity level in Alpena throughout September hovers around 79%.
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Average temperature
Maximum temperature
Humidity
In September, Alpena averages 77 mm (3.0 inches) of rainfall, typically over the course of 11 rainy days. The month enjoys an average of 12 hours 27 minutes of daylight, with the sun shining for approximately 9 hours 17 minutes each day. Additionally, there is a 50% probability of sunny days during this period.
Precipitation
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Chance of sun
In September, the UV Index in Alpena reaches a maximum of 7, indicating a level of High exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 25 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 | 3 | 4 | 6 | 7 | 7 | 6 | 4 | 3 | 1 | 1 |
| Exposure | Low | Moderate | High | Moderate | Low | ||||||||
| Time to burn | 45 min | 30 min | 25 min | 30 min | 45 min | ||||||||