Last updated: March 2, 2024
The weather in Herndon, United States, during April is characterized by an average temperature of 13°C (56°F). Highs can soar to 29°C (85°F), while lows may dip to 0°C (32°F). Typically, the humidity level in Herndon throughout April hovers around 84%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In April, Herndon averages 100 mm (3.9 inches) of rainfall, typically over the course of 12 rainy days. The month enjoys an average of 13 hours 14 minutes of daylight, with the sun shining for approximately 8 hours 26 minutes each day. Additionally, there is a 48% probability of sunny days during this period.
Precipitation
Rainy days
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Chance of sun
In April, the UV Index in Herndon reaches a maximum of 9, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 15 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 | 8 | 9 | 9 | 7 | 5 | 3 | 1 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | High | Moderate | Low | ||||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 25 min | 30 min | 45 min | ||||||