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
An increase in the average high-temperature marks May, moving from April's comfortable 64.9°F (18.3°C) to a moderately hot 75°F (23.9°C). Herndon experiences a mean low-temperature of 55°F (12.8°C) during May.Humidity
The average relative humidity in May in Herndon is 76%.Rainfall
In Herndon, Virginia, during May, the rain falls for 17.5 days and regularly aggregates up to 3.11" (79mm) of precipitation. Throughout the year, there are 158.1 rainfall days, and 31.46" (799mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Herndon.Daylight
In Herndon, Virginia, 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, in Herndon, sunrise is at 5:45 am and sunset at 8:28 pm EDT.
Sunshine
In May, the average sunshine in Herndon is 8.7h.UV index
May through August, with an average maximum UV index of 6, are months with the highest UV index in Herndon. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 6 during May translates into these guidelines:
Eschew overexposure. Those with light skin may suffer burns in fewer than 20 minutes. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Frequently asked questions
What are the temperatures in Herndon in May?
What is the average humidity in May in Herndon?
How much does it rain in Herndon in May?
When it does not snow in Herndon?
Does it snow in Herndon in May?
What is the average length of the day in May in Herndon?
When is the sunrise / sunset in May in Herndon?
How many hours of sunshine does Herndon have in May?
What is the month with the highest UV index in Herndon?
What is the UV index reading in May in Herndon?
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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