Last updated: March 2, 2024
The weather in Boulder, United States, during April is characterized by an average temperature of 5°C (42°F). Highs can soar to 22°C (72°F), while lows may dip to -11°C (13°F). Typically, the humidity level in Boulder throughout April hovers around 76%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In April, Boulder averages 68 mm (2.7 inches) of rainfall, typically over the course of 12 rainy days. The month enjoys an average of 13 hours 18 minutes of daylight, with the sun shining for approximately 10 hours 7 minutes each day. Additionally, there is a 51% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In April, the UV Index in Boulder 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 | 9 | 10 | 11 | 10 | 8 | 5 | 3 | 1 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | Extreme | VeryHigh | Moderate | Low | |||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 10 min | 15 min | 30 min | 45 min | |||||