Last updated: March 2, 2024
The weather in Alton, United States, during May is characterized by an average temperature of 19°C (67°F). Highs can soar to 31°C (87°F), while lows may dip to 7°C (45°F). Typically, the humidity level in Alton throughout May hovers around 83%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In May, Alton averages 181 mm (7.1 inches) of rainfall, typically over the course of 15 rainy days. The month enjoys an average of 14 hours 8 minutes of daylight, with the sun shining for approximately 9 hours 19 minutes each day. Additionally, there is a 30% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In May, the UV Index in Alton 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 | 2 | 4 | 6 | 8 | 10 | 11 | 10 | 8 | 6 | 3 | 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 | ||||