Last updated: March 2, 2024
The weather in Helena, United States, during December is characterized by an average temperature of 14°C (57°F). Highs can soar to 25°C (77°F), while lows may dip to 0°C (33°F). Typically, the humidity level in Helena throughout December hovers around 87%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In December, Helena averages 109 mm (4.3 inches) of rainfall, typically over the course of 11 rainy days. The month enjoys an average of 10 hours 11 minutes of daylight, with the sun shining for approximately 7 hours 14 minutes each day. Additionally, there is a 43% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In December, the UV Index in Helena reaches a maximum of 4, indicating a level of Moderate exposure. The most intense UV radiation typically occurs between 11:00 and 13:00, during which unprotected skin may burn in as little as 30 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 | 4 | 4 | 3 | 2 | 1 | 0 | 0 | 0 |
| Exposure | Low | Moderate | Low | ||||||||||
| Time to burn | 45 min | 30 min | 45 min | ||||||||||