Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
The commencement of May sees a shift in the average high-temperature, moving from a comfortable 64.9°F (18.3°C) in April to a moderately hot 75°F (23.9°C). In the month of May, Herndon experiences an average low-temperature of 55°F (12.8°C).Humidity
In May, the average relative humidity is 76%.Rainfall
In Herndon, in May, it is raining for 17.5 days, with typically 3.11" (79mm) of accumulated precipitation. In Herndon, during the entire year, the rain falls for 158.1 days and collects up to 31.46" (799mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In Herndon, the average length of the day in May is 14h and 19min.On the first day of the month, sunrise is at 6:10 am and sunset at 8:02 pm. On the last day of May, sunrise is at 5:45 am and sunset at 8:28 pm EDT.
Sunshine
In May, the average sunshine is 8.7h.UV index
May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In May, the maximum UV index of 6 suggests this advice:
Fend off overexposure. Sun protection is vital. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in May?
What is the average humidity in May?
How much does it rain in May?
When it does not snow?
Does it snow in May?
How many hours of daylight does Herndon have in May?
When are sunrise and sunset in May in Herndon?
How many hours of sunshine does Herndon have in May?
When is the highest UV index?
What is the UV index intensity in May?
Average temperature in May
Herndon, VA
- Average high temperature in May: 75°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in May: 55°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (25.9°F).
Average pressure in May
Herndon, VA
- Average pressure in May: 30.01"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in May
Herndon, VA
- Average wind speed in May: 6mph
The windiest month (with the highest average wind speed) is March (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in May
Herndon, VA
- Average humidity in May: 76%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (70%).
Average rainfall in May
Herndon, VA
- Average rainfall in May: 3.11"
The wettest month (with the highest rainfall) is August (3.78").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in May
Herndon, VA
- Average rainfall days in May: 17.5 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in May
Herndon, VA
- Average snowfall in May: 0"
The month with the highest snowfall is January (3.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Herndon, VA
- Average snowfall days in May: 0 days
The months with the highest number of snowfall days are January and February (5.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
Herndon, VA
- Average daylight in May: 14h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in May: 8h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 0min).
Average sunshine days in May
Herndon, VA
- Average sunshine days in May: 12.1 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in May
Herndon, VA
- Average UV index in May: 6
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in May
Herndon, VA
- Average cloud cover in May: 45
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in May
Herndon, VA
- Average visibility in May: 5mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Herndon, Virginia, USA
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