December weather forecast
Winthrop, MA

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Weather in December

December, the first month of the winter in Winthrop, is still a cold month, with an average temperature ranging between max 39.9°F (4.4°C) and min 29.7°F (-1.3°C).

Temperature

December ushers in a slight temperature change, with average high-temperatures reducing from November's chilly 49.5°F (9.7°C) to a cold 39.9°F (4.4°C). Winthrop's average low-temperature is measured at a subzero cold 29.7°F (-1.3°C) during December.

Humidity

The average relative humidity in December is 76%.

Rainfall

The wettest months are March, April and December, with an average 2.91" (74mm) of rainfall.

Snowfall

Months with snowfall are January through May, October through December. In Winthrop, in December, snow falls for 5.2 days, with typically accumulated 2.83" (72mm) of snow. Throughout the year, there are 29.8 snowfall days, and 15.75" (400mm) of snow is accumulated.

Ocean temperature

In Winthrop, the average seawater temperature in December is 46.2°F (7.9°C).
Note: Swimming in 46.2°F (7.9°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

With an average of 9h and 6min of daylight, December has the shortest days of the year in Winthrop.
On the first day of December in Winthrop, sunrise is at 6:54 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.

Sunshine

In December, the average sunshine in Winthrop, Massachusetts, is 4.7h.

UV index

The months with the lowest UV index in Winthrop, Massachusetts, are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum daily UV index of 2 during December morphs into the following directions:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
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Frequently asked questions

How cold does it get in Winthrop in December?

The average high-temperature, in December, in Winthrop, is 39.9°F (4.4°C), while the average low-temperature is 29.7°F (-1.3°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in July is computed to be 86°F (30°C).

What is the average humidity in December in Winthrop?

The average relative humidity in December is 76%.

What is the rainiest month in Winthrop?

The months with the most rainfall in Winthrop, Massachusetts, are March, April and December, with an average 2.91" (74mm) of precipitation.

How many days does it rain in December in Winthrop?

In Winthrop, in December, it is raining for 10.1 days, with typically 2.91" (74mm) of accumulated precipitation.

How much does it snow in Winthrop in December?

In Winthrop, Massachusetts, during December, snow falls for 5.2 days and regularly aggregates up to 2.83" (72mm) of snow.

What is the water temperature in December in Winthrop?

In Winthrop, in December, the average water temperature is 46.2°F (7.9°C). Swimming in 46.2°F (7.9°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

What is the month with the shortest days in Winthrop?

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 Winthrop?

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

When are sunrise and sunset in December in Winthrop?

In December, on the first day of the month, sunrise is at 6:54 am and sunset at 4:12 pm. On the last day of the month, in Winthrop, Massachusetts, sunrise is at 7:13 am and sunset at 4:21 pm EST.

How many hours of sunshine does Winthrop have in December?

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

When is the lowest UV index in Winthrop?

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

What is the UV index reading in December in Winthrop?

In December, the average daily maximum UV index in Winthrop, Massachusetts, is 2. A UV Index of 2, and less, symbolizes 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
Winthrop, MA

Average temperature in December - Winthrop, MA
  • Average high temperature in December: 39.9°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (34.2°F).

  • Average low temperature in December: 29.7°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).

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Average pressure in December
Winthrop, MA

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

The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

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Average wind speed in December
Winthrop, MA

Average wind speed in December - Winthrop, MA
  • Average wind speed in December: 9.4mph

The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).

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Average humidity in December
Winthrop, MA

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

The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (69%).

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Average rainfall in December
Winthrop, MA

Average rainfall in December - Winthrop, MA
  • Average rainfall in December: 2.91"

The wettest months (with the highest rainfall) are March, April and December (2.91").
The driest month (with the least rainfall) is September (1.26").

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Average rainfall days in December
Winthrop, MA

Average rainfall days in December - Winthrop, MA
  • Average rainfall days in December: 10.1 days

The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (7.9 days).

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Average snowfall in December
Winthrop, MA

Average snowfall in December - Winthrop, MA
  • Average snowfall in December: 2.83"

The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in December
Winthrop, MA

Average snowfall days in December - Winthrop, MA
  • Average snowfall days in December: 5.2 days

The months with the highest number of snowfall days are January and February (7.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average sea temperature in December
Winthrop, MA

Average sea temperature in December - Winthrop, MA
  • Average sea temperature in December: 46.3°F

The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is March (38.8°F).

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

Average daylight in December / Average sunshine in December - Winthrop, 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 4min

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).

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Average sunshine days in December
Winthrop, MA

Average sunshine days in December - Winthrop, MA
  • Average sunshine days in December: 16.5 days

The month with the most sunshine days is September (17.7 days).
The month with the least sunshine days is April (13 days).

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Average UV index in December
Winthrop, MA

Average UV index in December - Winthrop, 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).

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Average cloud cover in December
Winthrop, MA

Average cloud cover in December - Winthrop, 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).

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Average visibility in December
Winthrop, MA

Average visibility in December - Winthrop, MA
  • 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).

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Winthrop, Massachusetts, USA

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