December weather forecastThornhill, KY

December

Weather in December

The first month of the winter, December, is also a frosty month in Thornhill, Kentucky, with an average temperature fluctuating between 31.8°F (-0.1°C) and 44.1°F (6.7°C).

Temperature

The onset of December is marked by a minor decrease in temperature, transitioning from a fresh 53.1°F (11.7°C) in November to a chilly 44.1°F (6.7°C). In Thornhill, December is marked by an average low-temperature of 31.8°F (-0.1°C).

Humidity

The months with the highest humidity are February and December, with an average relative humidity of 80%.

Rainfall

In Thornhill, during December, the rain falls for 13 days and regularly aggregates up to 2.6" (66mm) of precipitation. In Thornhill, during the entire year, the rain falls for 168.9 days and collects up to 34.09" (866mm) of precipitation.

Snowfall

Months with snowfall in Thornhill are January through April, November and December. In Thornhill, in December, snow falls for 5.9 days, with typically accumulated 1.38" (35mm) of snow. In Thornhill, during the entire year, snow falls for 28.3 days and aggregates up to 7.72" (196mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 36min of daylight.
On the first day of December, sunrise is at 7:41 am and sunset at 5:22 pm. On the last day of the month, sunrise is at 7:59 am and sunset at 5:32 pm EST.

Sunshine

In December, the average sunshine is 4.4h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.
Note: A maximum daily UV index of 2 during December morphs into the following directions:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Avoiding the Sun during its peak radiation time around midday is a healthy practice. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Updated: Jul 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In Thornhill, in December, the average high-temperature is 44.1°F (6.7°C), and the average low-temperature is 31.8°F (-0.1°C). The average heat index (a.k.a. 'real feel', 'feels like'), which factors the actual air temperature with the relative humidity, in August is estimated at 95°F (35°C).

February and December, with an average relative humidity of 80%, are most humid months.

The average relative humidity in December is 80%.

In Thornhill, in December, during 13 rainfall days, 2.6" (66mm) of precipitation is typically accumulated.

In Thornhill, in December, during 5.9 snowfall days, 1.38" (35mm) of snow is typically accumulated.

With an average of 9h and 36min of daylight, December has the shortest days of the year.

In December, the average day length in Thornhill, Kentucky, is 9h and 33min.

On the first day of December, sunrise is at 7:41 am and sunset at 5:22 pm. On the last day of the month, sunrise is at 7:59 am and sunset at 5:32 pm EST.

In December, the average sunshine duration is 4.4h.

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

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Thornhill, KY

  • Average high temperature in December: 44.1°F

The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (38.8°F).

  • Average low temperature in December: 31.8°F

The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (25.9°F).

Average pressure in December
Thornhill, KY

  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in December
Thornhill, KY

  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).

Average humidity in December
Thornhill, KY

  • Average humidity in December: 80%

The months with the highest relative humidity are February and December (80%).
The month with the lowest relative humidity is August (73%).

Average rainfall in December
Thornhill, KY

  • Average rainfall in December: 2.6"

The wettest month (with the highest rainfall) is April (3.98").
The driest month (with the least rainfall) is September (1.85").

Average rainfall days in December
Thornhill, KY

  • Average rainfall days in December: 13 days

The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is February (10.6 days).

Average snowfall in December
Thornhill, KY

  • Average snowfall in December: 1.38"

The month with the highest snowfall is February (2.05").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Thornhill, KY

  • Average snowfall days in December: 5.9 days

The month with the highest number of snowfall days is January (8.3 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
Thornhill, KY

  • Average daylight in December: 9h and 36min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in December: 4h and 24min

The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).

Average sunshine days in December
Thornhill, KY

  • Average sunshine days in December: 13.9 days

The month with the most sunshine days is October (17.9 days).
The month with the least sunshine days is May (10.2 days).

Average UV index in December
Thornhill, 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, November and December (UV index 2).

Average cloud cover in December
Thornhill, KY

  • Average cloud cover in December: 55

The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 28).

Average visibility in December
Thornhill, KY

  • Average visibility in December: 5mi

The months with the highest visibility are March, April, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, May and December (5mi).