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
The arrival of April sees a shift in the average high-temperature, moving from a chilly 46°F (7.8°C) in March to a refreshing 58.3°F (14.6°C). Herndon observes an average low-temperature of 39.7°F (4.3°C) during April nights.Humidity
April is the least humid month in Herndon, Pennsylvania, with an average relative humidity of 76%.Rainfall
In Herndon, during April, the rain falls for 17.8 days and regularly aggregates up to 3.19" (81mm) of precipitation. Throughout the year, there are 165.3 rainfall days, and 30.55" (776mm) of precipitation is accumulated.Snowfall
Months with snowfall in Herndon are January through May, October through December. In April, it is snowing for 1 days. Throughout April, 0.35" (9mm) of snow is accumulated. Throughout the year, in Herndon, there are 38.1 snowfall days, and 17.68" (449mm) of snow is accumulated.Daylight
The average length of the day in April in Herndon 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 Herndon, the average sunshine in April is 8h.UV index
In Herndon, the average daily maximum UV index in April is 3. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.Note: A daily maximum UV index of 3 in April translates into the following instructions:
Guard yourself - An obligation to protect skin and eyes from harm exists. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Frequently asked questions
What are April temperatures in Herndon?
What is the least humid month in Herndon?
What is the average humidity in April in Herndon?
How much does it rain in Herndon in April?
How much does it snow in Herndon in April?
How many hours of daylight does Herndon have in April?
What time are sunrise and sunset in April in Herndon?
How long on average sun shines in April in Herndon?
How high is the UV index in April in Herndon?
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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