December weather forecast
Derby, CT

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Weather in December

December brings the year in Derby to a close, wrapped in the cold embrace of winter. The city experiences its highest rainfall in this month, at 4.06" (103mm). Drops in temperatures turn the precipitation into snow, casting a pristine winter wonderland scenery. As the year ends, Derby hunkers down, ready to embrace another January of cold and snow.

Temperature

With December's arrival, Derby, Connecticut, sees a decrease in average high-temperatures, moving from a chilly 49.8°F (9.9°C) in November to a wintry 40.3°F (4.6°C). Derby's nights in December maintain a consistent average of 31.3°F (-0.4°C), demonstrating a minimal differential from its daytime temperature.

Humidity

In Derby, the average relative humidity in December is 76%.

Rainfall

December is the month with the most rainfall. Rain falls for 12.8 days and accumulates 4.06" (103mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall. In Derby, in December, snow falls for 4.6 days, with typically accumulated 2.4" (61mm) of snow. Throughout the year, in Derby, there are 27.3 snowfall days, and 11.42" (290mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 9h and 18min of daylight.
On the first day of the month, sunrise is at 6:59 am and sunset at 4:23 pm. On the last day of December, sunrise is at 7:18 am and sunset at 4:33 pm EST.

Sunshine

In Derby, the average sunshine in December is 4.9h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for average individuals.
Note: A maximum UV index of 2 in December translates into the following recommendations:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Derby in December?

During December, Derby experiences an average high-temperature of 40.3°F (4.6°C) and a low-temperature of 31.3°F (-0.4°C). In July, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which represents the influence of relative humidity on air temperature, is computed to be 87.8°F (31°C).

What is the average humidity in December in Derby?

The average relative humidity in December in Derby, Connecticut, is 76%.

What is the rainiest month in Derby?

The month with the most rainfall in Derby is December, when the rain falls for 12.8 days and typically aggregates up to 4.06" (103mm) of precipitation.

How many days does it rain in December in Derby?

In Derby, Connecticut, during December, the rain falls for 12.8 days and regularly aggregates up to 4.06" (103mm) of precipitation.

How many days does it snow in December in Derby?

In Derby, Connecticut, in December, snow falls for 4.6 days, with typically accumulated 2.4" (61mm) of snow.

What is the month with the shortest days in Derby?

With an average of 9h and 18min of daylight, December has the shortest days of the year.

How many hours of daylight does Derby have in December?

In Derby, the average day length in December is 9h and 15min.

What time are sunrise and sunset in December in Derby?

On the first day of December in Derby, Connecticut, sunrise is at 6:59 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:33 pm EST.

How many hours of sunshine does Derby have in December?

In Derby, Connecticut, the average sunshine duration in December is 4.9h.

What is the month with the lowest UV index in Derby?

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

What is the UV index reading in December in Derby?

In December, the average daily maximum UV index in Derby, Connecticut, is 2. A UV Index of 2, and less, symbolizes a low health risk from unprotected exposure to 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
Derby, CT

Average temperature in December - Derby, CT
  • Average high temperature in December: 40.3°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (34.7°F).

  • Average low temperature in December: 31.3°F

The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).

Average pressure in December
Derby, CT

Average pressure in December - Derby, CT
  • Average pressure in December: 30.06"Hg

The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Derby, CT

Average wind speed in December - Derby, CT
  • Average wind speed in December: 9.3mph

The windiest month (with the highest average wind speed) is January (9.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).

Average humidity in December
Derby, CT

Average humidity in December - Derby, CT
  • Average humidity in December: 76%

The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (72%).

Average rainfall in December
Derby, CT

Average rainfall in December - Derby, CT
  • Average rainfall in December: 4.06"

The wettest month (with the highest rainfall) is December (4.06").
The driest month (with the least rainfall) is September (2.24").

Average rainfall days in December
Derby, CT

Average rainfall days in December - Derby, CT
  • Average rainfall days in December: 12.8 days

The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is January (9.4 days).

Average snowfall in December
Derby, CT

Average snowfall in December - Derby, CT
  • Average snowfall in December: 2.4"

The month with the highest snowfall is February (3.23").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Derby, CT

Average snowfall days in December - Derby, CT
  • Average snowfall days in December: 4.6 days

The month with the highest number of snowfall days is February (7.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Derby, CT

Average daylight in December / Average sunshine in December - Derby, CT
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in December: 4h and 5min

The months with the most sunshine are July and August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in December
Derby, CT

Average sunshine days in December - Derby, CT
  • Average sunshine days in December: 14.5 days

The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (10.3 days).

Average UV index in December
Derby, CT

Average UV index in December - Derby, CT
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

Average cloud cover in December
Derby, CT

Average cloud cover in December - Derby, CT
  • Average cloud cover in December: 48

The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in December
Derby, CT

Average visibility in December - Derby, CT
  • 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).

Derby, Connecticut, USA

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