December weather forecast
Simsbury, CT

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The iconic old tower set amid dense tree cover in Simsbury, Connecticut
The iconic old tower set amid dense tree cover in Simsbury, Connecticut

Weather in December

With December, winter is in full swing in Simsbury, Connecticut, as the overall temperature slides further down to an average high of 37.6°F (3.1°C). The quiet fall of snow showers, coupled with decorated streets and houses, ushers in the festive spirit. December watches the precipitation shift from rain to snow, with an average snowfall of 3.54" (90mm), redefining the cityscape. The weather paints a perfect backdrop for holiday celebrations and snow-related activities. Simsbury shimmers under a pristine white velvet, wrapping the year on a magical note.

Temperature

In December, the meteorological conditions alter, with the average high-temperature shifting from a frosty 48.2°F (9°C) in November to a wintry 37.6°F (3.1°C). During December, the average low-temperature is recorded at a freezing cold 26.8°F (-2.9°C).

Humidity

The average relative humidity in December in Simsbury is 79%.

Rainfall

December is the month with the most rainfall. Rain falls for 10.5 days and accumulates 3.43" (87mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In December, it is snowing for 6.1 days. Throughout December, 3.54" (90mm) of snow is accumulated. In Simsbury, during the entire year, snow falls for 33.1 days and aggregates up to 18.39" (467mm) of snow.

Daylight

The month with the shortest days in Simsbury is December, with an average of 9h and 12min of daylight.
On the first day of the month, sunrise is at 6:59 am and sunset at 4:21 pm. On the last day of December, in Simsbury, sunrise is at 7:18 am and sunset at 4:30 pm EST.

Sunshine

The average sunshine in December in Simsbury is 4.7h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Simsbury. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: The UV index of 2 in December translates into these instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Simsbury?

In Simsbury, in December, the average high-temperature is 37.6°F (3.1°C), and the average low-temperature is 26.8°F (-2.9°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in July is calculated to be 87.8°F (31°C).

What is the average humidity in December in Simsbury?

In December, the average relative humidity in Simsbury is 79%.

What is the rainiest month in Simsbury?

The month with the most rainfall in Simsbury, Connecticut, is December, when the rain falls for 10.5 days and typically aggregates up to 3.43" (87mm) of precipitation.

How much does it rain in Simsbury in December?

In Simsbury, Connecticut, during December, the rain falls for 10.5 days and regularly aggregates up to 3.43" (87mm) of precipitation.

How much does it snow in Simsbury in December?

In Simsbury, Connecticut, during December, snow falls for 6.1 days and regularly aggregates up to 3.54" (90mm) of snow.

What is the month with the shortest days in Simsbury?

The month with the shortest days in Simsbury, Connecticut, is December, with an average of 9h and 12min of daylight.

What is the average length of the day in December in Simsbury?

In Simsbury, the average day length in December is 9h and 12min.

What time are sunrise and sunset in December in Simsbury?

In December, on the first day of the month, sunrise is at 6:59 am and sunset at 4:21 pm. On the last day of the month, in Simsbury, sunrise is at 7:18 am and sunset at 4:30 pm EST.

How long on average sun shines in December in Simsbury?

The average sunshine duration in December in Simsbury, Connecticut, is 4.7h.

When is the lowest UV index in Simsbury?

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

What is the UV index reading in December in Simsbury?

In December, the average daily maximum UV index in Simsbury, Connecticut, is 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to UV radiation.
Average high temperature
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
Simsbury, CT

Average temperature in December - Simsbury, CT
  • Average high temperature in December: 37.6°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (32°F).

  • Average low temperature in December: 26.8°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).

Average pressure in December
Simsbury, CT

Average pressure in December - Simsbury, 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
Simsbury, CT

Average wind speed in December - Simsbury, CT
  • Average wind speed in December: 7.8mph

The windiest months (with the highest average wind speed) are January and March (8.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.2mph).

Average humidity in December
Simsbury, CT

Average humidity in December - Simsbury, CT
  • Average humidity in December: 79%

The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (71%).

Average rainfall in December
Simsbury, CT

Average rainfall in December - Simsbury, CT
  • Average rainfall in December: 3.43"

The wettest month (with the highest rainfall) is December (3.43").
The driest month (with the least rainfall) is September (1.97").

Average rainfall days in December
Simsbury, CT

Average rainfall days in December - Simsbury, CT
  • Average rainfall days in December: 10.5 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is January (9.4 days).

Average snowfall in December
Simsbury, CT

Average snowfall in December - Simsbury, CT
  • Average snowfall in December: 3.54"

The month with the highest snowfall is February (5.24").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Simsbury, CT

Average snowfall days in December - Simsbury, CT
  • Average snowfall days in December: 6.1 days

The month with the highest number of snowfall days is February (8.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Simsbury, CT
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in December: 4h and 4min

The months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in December
Simsbury, CT

Average sunshine days in December - Simsbury, CT
  • Average sunshine days in December: 15.7 days

The month with the most sunshine days is January (17.1 days).
The month with the least sunshine days is June (11.6 days).

Average UV index in December
Simsbury, CT

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

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 December
Simsbury, CT

Average cloud cover in December - Simsbury, CT
  • Average cloud cover in December: 49

The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in December
Simsbury, CT

Average visibility in December - Simsbury, CT
  • Average visibility in December: 6mi

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

Simsbury, Connecticut, USA

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