December weather forecast
Herndon, KY

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Weather in December

The first month of the winter, December, is still a chilly month in Herndon, Kentucky, with an average temperature varying between 34.7°F (1.5°C) and 47.3°F (8.5°C).

Temperature

The transition into December subtly indicates a reduction in the average high-temperature, down to a frosty 47.3°F (8.5°C) from November's moderate 56.1°F (13.4°C). Herndon's temperature drops to an average low of 34.7°F (1.5°C) during the nights of December.

Humidity

In December, the average relative humidity in Herndon is 78%.

Rainfall

In Herndon, in December, it is raining for 12.4 days, with typically 3.5" (89mm) of accumulated precipitation. In Herndon, during the entire year, the rain falls for 179.3 days and collects up to 39.76" (1010mm) of precipitation.

Snowfall

Months with snowfall are January through April, October through December. In December, in Herndon, it is snowing for 3.1 days. Throughout December, 1.18" (30mm) of snow is accumulated. In Herndon, during the entire year, snow falls for 15.8 days and aggregates up to 5.35" (136mm) of snow.

Daylight

December has the shortest days of the year in Herndon, Kentucky, with an average of 9h and 42min of daylight.
On the first day of December in Herndon, sunrise is at 6:44 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 4:44 pm CST.

Sunshine

In December, the average sunshine is 4.7h.

UV index

January, February and December, with an average maximum UV index of 2, are months with the lowest UV index in Herndon. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: The maximum UV index of 2 during December leads to these instructions:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in Herndon in December?

The high-temperature, in December, in Herndon, records 47.3°F (8.5°C), while the low-temperature is 34.7°F (1.5°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines relative humidity and air temperature, in September is calculated to be 84.2°F (29°C).

What is the average humidity in December in Herndon?

In December, the average relative humidity in Herndon is 78%.

How much does it rain in Herndon in December?

In Herndon, in December, it is raining for 12.4 days, with typically 3.5" (89mm) of accumulated precipitation.

How much does it snow in Herndon in December?

In Herndon, in December, during 3.1 snowfall days, 1.18" (30mm) of snow is typically accumulated.

What is the month with the shortest days in Herndon?

The month with the shortest days in Herndon, Kentucky, is December, with an average of 9h and 42min of daylight.

How many hours of daylight does Herndon have in December?

In Herndon, the average day length in December is 9h and 42min.

When is the sunrise / sunset in December in Herndon?

On the first day of December, sunrise is at 6:44 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 4:44 pm CST.

How many hours of sunshine does Herndon have in December?

In Herndon, Kentucky, the average sunshine duration in December is 4.7h.

What are the months with the lowest UV index in Herndon?

January, February and December, with an average maximum UV index of 2, are months with the lowest UV index in Herndon.

What is the UV index intensity in December in Herndon?

In Herndon, Kentucky, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Herndon, KY

Average temperature in December - Herndon, KY
  • Average high temperature in December: 47.3°F

The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (42.6°F).

  • Average low temperature in December: 34.7°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (28.9°F).

Average pressure in December
Herndon, KY

Average pressure in December - Herndon, KY
  • Average pressure in December: 30.14"Hg

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).

Average wind speed in December
Herndon, KY

Average wind speed in December - Herndon, KY
  • Average wind speed in December: 8.2mph

The windiest months (with the highest average wind speed) are February and April (8.8mph).
The calmest month (with the lowest average wind speed) is July (5.2mph).

Average humidity in December
Herndon, KY

Average humidity in December - Herndon, KY
  • Average humidity in December: 78%

The months with the highest relative humidity are March and May (79%).
The month with the lowest relative humidity is October (72%).

Average rainfall in December
Herndon, KY

Average rainfall in December - Herndon, KY
  • Average rainfall in December: 3.5"

The wettest month (with the highest rainfall) is February (4.06").
The driest month (with the least rainfall) is September (2.17").

Average rainfall days in December
Herndon, KY

Average rainfall days in December - Herndon, KY
  • Average rainfall days in December: 12.4 days

The month with the highest number of rainy days is July (19.6 days).
The month with the least rainy days is November (10.8 days).

Average snowfall in December
Herndon, KY

Average snowfall in December - Herndon, KY
  • Average snowfall in December: 1.18"

The month with the highest snowfall is January (1.42").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Herndon, KY

Average snowfall days in December - Herndon, KY
  • Average snowfall days in December: 3.1 days

The month with the highest number of snowfall days is January (4.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Herndon, KY

Average daylight in December / Average sunshine in December - Herndon, KY
  • Average daylight in December: 9h and 4min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • Average sunshine in December: 4h and 4min

The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).

Average sunshine days in December
Herndon, KY

Average sunshine days in December - Herndon, KY
  • Average sunshine days in December: 15.5 days

The months with the most sunshine days are October and November (17.8 days).
The month with the least sunshine days is July (8.6 days).

Average UV index in December
Herndon, KY

Average UV index in December - Herndon, KY
  • Average UV index in December: 2

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 and December (UV index 2).

Average cloud cover in December
Herndon, KY

Average cloud cover in December - Herndon, KY
  • Average cloud cover in December: 50

The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 29).

Average visibility in December
Herndon, KY

Average visibility in December - Herndon, KY
  • Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Herndon, Kentucky, USA

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