December weather forecast
Winchester, MA

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Weather in December

The first month of the winter, December, is also a wintry month in Winchester, Massachusetts, with an average temperature varying between 28.9°F (-1.7°C) and 38.8°F (3.8°C).

Temperature

During the transition into December, Winchester observes a decrease in the average high-temperature, falling from a frosty 49.1°F (9.5°C) in November to a wintry 38.8°F (3.8°C). Winchester witnesses a consistent average low-temperature of 28.9°F (-1.7°C) throughout December.

Humidity

In December, the average relative humidity is 76%.

Rainfall

December is the month with the most rainfall. Rain falls for 9.2 days and accumulates 2.87" (73mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Winchester, in December, snow falls for 5.5 days, with typically accumulated 4.33" (110mm) of snow. In Winchester, during the entire year, snow falls for 30.6 days and aggregates up to 18.86" (479mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 6min of daylight.
On the first day of the month, sunrise is at 6:55 am and sunset at 4:12 pm. On the last day of December, sunrise is at 7:13 am and sunset at 4:21 pm EST.

Sunshine

In Winchester, the average sunshine in December is 4.8h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: The maximum UV index of 2 during December translates into these guidelines:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.

Frequently asked questions

How cold is December?

The high-temperature, in December, in Winchester, records 38.8°F (3.8°C), while the low-temperature is 28.9°F (-1.7°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which factors the actual air temperature with the relative humidity, in August is calculated to be 84.2°F (29°C).

What is the average humidity in December?

In December, the average relative humidity is 76%.

What is the wettest month?

The month with the most rainfall is December, when the rain falls for 9.2 days and typically aggregates up to 2.87" (73mm) of precipitation.

How many days does it rain in December in Winchester?

In Winchester, Massachusetts, during December, the rain falls for 9.2 days and regularly aggregates up to 2.87" (73mm) of precipitation.

How much does it snow in December?

In Winchester, in December, during 5.5 snowfall days, 4.33" (110mm) of snow is typically accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 6min of daylight.

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

In December, the average day length is 9h and 8min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:55 am and sunset at 4:12 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:21 pm EST.

How many hours of sunshine does Winchester have in December?

The average sunshine duration in December is 4.8h.

When is the lowest UV index in Winchester?

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 intensity in December in Winchester?

In December, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability 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
Winchester, MA

Average temperature in December - Winchester, MA
  • Average high temperature in December: 38.8°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.1°F).

  • Average low temperature in December: 28.9°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

Average pressure in December
Winchester, MA

Average pressure in December - Winchester, MA
  • Average pressure in December: 30.03"Hg

The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Winchester, MA

Average wind speed in December - Winchester, MA
  • Average wind speed in December: 8.9mph

The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).

Average humidity in December
Winchester, MA

Average humidity in December - Winchester, MA
  • Average humidity in December: 76%

The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (69%).

Average rainfall in December
Winchester, MA

Average rainfall in December - Winchester, MA
  • Average rainfall in December: 2.87"

The wettest month (with the highest rainfall) is December (2.87").
The driest month (with the least rainfall) is September (1.22").

Average rainfall days in December
Winchester, MA

Average rainfall days in December - Winchester, MA
  • Average rainfall days in December: 9.2 days

The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is January (7.4 days).

Average snowfall in December
Winchester, MA

Average snowfall in December - Winchester, MA
  • Average snowfall in December: 4.33"

The month with the highest snowfall is February (4.96").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Winchester, MA

Average snowfall days in December - Winchester, MA
  • Average snowfall days in December: 5.5 days

The month with the highest number of snowfall days is January (7.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Winchester, MA

Average daylight in December / Average sunshine in December - Winchester, MA
  • 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 6min).

  • Average sunshine in December: 4h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in December
Winchester, MA

Average sunshine days in December - Winchester, MA
  • Average sunshine days in December: 17.2 days

The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is April (13.3 days).

Average UV index in December
Winchester, MA

Average UV index in December - Winchester, MA
  • 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
Winchester, MA

Average cloud cover in December - Winchester, MA
  • Average cloud cover in December: 48

The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in December
Winchester, MA

Average visibility in December - Winchester, MA
  • Average visibility in December: 6mi

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

Winchester, Massachusetts, USA

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