May Weather in Herndon

Last updated: March 2, 2024

The weather in Herndon, United States, during May is characterized by an average temperature of 19°C (66°F). Highs can soar to 33°C (91°F), while lows may dip to 5°C (41°F). Typically, the humidity level in Herndon throughout May hovers around 78%.

5°C (41°F)

Minimum temperature

19°C (66°F)

Average temperature

33°C (91°F)

Maximum temperature

78%

Humidity

Precipitation and Sunshine hours

In May, Herndon averages 131 mm (5.2 inches) of rainfall, typically over the course of 13 rainy days. The month enjoys an average of 14 hours 18 minutes of daylight, with the sun shining for approximately 8 hours 43 minutes each day. Additionally, there is a 41% probability of sunny days during this period.

131 mm (5.2 inches)

Precipitation

13 rainy days

Rainy days

8 hours 43 minutes

Sunshine hours

41%

Chance of sun

UV Index

In May, the UV Index in Herndon reaches a maximum of 10, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 12:00 and 14:00, during which unprotected skin may burn in as little as 15 minutes.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
	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	3	5	8	10	10	10	8	6	3	2	1
Exposure	Low		Moderate		VeryHigh					High	Moderate	Low
Time to burn	45 min		30 min		15 min					25 min	30 min	45 min