Contents
- Weather in April
- Frequently asked questions
- Average temperature in April
- Average pressure in April
- Average wind speed in April
- Average humidity in April
- Average rainfall in April
- Average rainfall days in April
- Average snowfall in April
- Average snowfall days in April
- Average daylight in April
- Average sunshine in April
- Average sunshine days in April
- Average UV index in April
- Average cloud cover in April
- Average visibility in April
Weather in April
Temperature
With the onset of April, the average high-temperature slightly shifts from March's chilly 46°F (7.8°C) to a moderate 58.3°F (14.6°C). Herndon cools down to an average low-temperature of 39.7°F (4.3°C) throughout the month of April.Humidity
With an average relative humidity of 76%, April is the least humid month.Rainfall
In Herndon, in April, it is raining for 17.8 days, with typically 3.19" (81mm) of accumulated precipitation. In Herndon, during the entire year, the rain falls for 165.3 days and collects up to 30.55" (776mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Herndon, in April, during 1 snowfall days, 0.35" (9mm) of snow is typically accumulated. In Herndon, during the entire year, snow falls for 38.1 days and aggregates up to 17.68" (449mm) of snow.Daylight
In April, the average length of the day is 13h and 19min.On the first day of the month, sunrise is at 6:49 am and sunset at 7:32 pm. On the last day of April, sunrise is at 6:06 am and sunset at 8:02 pm EDT.
Sunshine
In April, the average sunshine is 8h.UV index
In April, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: A maximum UV index of 3 in April translates into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average April temperature?
What is the least humid month?
What is the average humidity in April?
How many days does it rain in April?
How much does it snow in April?
How many hours of daylight does Herndon have in April?
When is the sunrise / sunset in April?
How many hours of sunshine does Herndon have in April?
What is the UV index reading in April?
Average temperature in April
Herndon, PA
- Average high temperature in April: 58.3°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in April: 39.7°F
The month with the highest average low temperature is July (61.2°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in April
Herndon, PA
- Average pressure in April: 29.98"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in April
Herndon, PA
- Average wind speed in April: 7.8mph
The windiest months (with the highest average wind speed) are March and April (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in April
Herndon, PA
- Average humidity in April: 76%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (76%).
Average rainfall in April
Herndon, PA
- Average rainfall in April: 3.19"
The wettest month (with the highest rainfall) is May (3.35").
The driest months (with the least rainfall) are February and November (2.09").
Average rainfall days in April
Herndon, PA
- Average rainfall days in April: 17.8 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is February (9 days).
Average snowfall in April
Herndon, PA
- Average snowfall in April: 0.35"
The month with the highest snowfall is February (5.67").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in April
Herndon, PA
- Average snowfall days in April: 1 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in April /
Average sunshine in April
Herndon, PA
- Average daylight in April: 13h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in April: 8h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in April
Herndon, PA
- Average sunshine days in April: 10.9 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is May (9.9 days).
Average UV index in April
Herndon, PA
- Average UV index in April: 3
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in April
Herndon, PA
- Average cloud cover in April: 47
The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in April
Herndon, PA
- Average visibility in April: 6mi
The months with the highest visibility are March, April, June, July and November (6mi).
The months with the lowest visibility are January, February, May, August, September, October and December (5mi).
Herndon, Pennsylvania, USA
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