Last updated: March 2, 2024
The weather in Helena, United States, during May is characterized by an average temperature of 20°C (69°F). Highs can soar to 33°C (92°F), while lows may dip to 7°C (44°F). Typically, the humidity level in Helena throughout May hovers around 82%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In May, Helena averages 143 mm (5.6 inches) of rainfall, typically over the course of 13 rainy days. The month enjoys an average of 14 hours 7 minutes of daylight, with the sun shining for approximately 9 hours 42 minutes each day. Additionally, there is a 35% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In May, the UV Index in Helena reaches a maximum of 11, indicating a level of Extreme exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 10 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 | 11 | 11 | 9 | 7 | 4 | 2 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | Extreme | VeryHigh | High | Moderate | Low | ||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 10 min | 15 min | 25 min | 30 min | 45 min | ||||