December weather forecast
Lynn, MA

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Large rocks on the shores of the coast of Lynn Massachusetts
Large rocks on the shores of the coast of Lynn Massachusetts

Weather in December

Finally, December greets Lynn with a distinct winter chill, recording an average temperature drop to 30.2°F (-1°C). This month sees an upward spike in snowfall, reaching 3.43" (87mm) indicating that Christmas is round the corner. The sea temperature falls further, discouraging all but the bravest from taking a dip. Limited sunlight and increased rainfall make this month a perfect time for warm foods and indoor activities, wrapping up the year on a cosy note.

Temperature

The average high-temperature drops in December, from November's frosty 49.5°F (9.7°C) to a cold 39.9°F (4.4°C). Nighttime temperatures consistently average a freezing cold 30.2°F (-1°C) during December.

Humidity

In December, the average relative humidity is 76%.

Rainfall

The month with the most rainfall is December, when the rain falls for 10.3 days and typically aggregates up to 2.99" (76mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In Lynn, in December, snow falls for 5.3 days, with typically accumulated 3.43" (87mm) of snow. Throughout the year, there are 29.9 snowfall days, and 15.59" (396mm) of snow is accumulated.

Ocean temperature

In Lynn, the average seawater temperature in December is 46.2°F (7.9°C).
Note: Swimming at temperatures less than 50°F (10°C) in 46.2°F (7.9°C) is feasible with the right swimsuit; if not, expect cold shock and breathlessness. A quick swim at 55.4°F (13°C) without adequate warmth can be discomforting.

Daylight

With an average of 9h and 6min of daylight, December has the shortest days of the year.
On the first day of December in Lynn, sunrise is at 6:54 am and sunset at 4:11 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:21 pm EST.

Sunshine

February and December, with an average of 4.6h of sunshine, are months with the least sunshine.

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 minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

Frequently asked questions

Is it cold in Lynn during December?

In December, in Lynn, the average high-temperature is 39.9°F (4.4°C), and the average low-temperature is 30.2°F (-1°C).

What is the average humidity in December?

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

What is the wettest month?

The month with the most rainfall is December, when the rain falls for 10.3 days and typically aggregates up to 2.99" (76mm) of precipitation.

How much does it rain in December?

In December, the rain falls for 10.3 days. Throughout December, 2.99" (76mm) of precipitation is accumulated.

How much does it snow in December?

In December, it is snowing for 5.3 days. Throughout December, 3.43" (87mm) of snow is accumulated.

How cold is the water in December?

In Lynn, the average seawater temperature in December is 46.2°F (7.9°C). 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.

What is the month with the shortest days?

With an average of 9h and 6min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

The average day length in December is 9h and 8min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:54 am and sunset at 4:11 pm. On the last day of the month, in Lynn, sunrise is at 7:13 am and sunset at 4:21 pm EST.

What is the month with the least sunshine?

The months with the least sunshine are February and December, with an average of 4.6h of sunshine.

How long on average sun shines in December?

In December, the average sunshine duration is 4.6h.

When is the lowest UV index?

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

What is the UV index reading in December in Lynn?

The average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from exposure to Sun's UV rays.
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
Lynn, MA

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

The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (34.2°F).

  • Average low temperature in December: 30.2°F

The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).

Average pressure in December
Lynn, MA

Average pressure in December - Lynn, 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 (29.92"Hg).

Average wind speed in December
Lynn, MA

Average wind speed in December - Lynn, MA
  • Average wind speed in December: 10.3mph

The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in December
Lynn, MA

Average humidity in December - Lynn, 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 (70%).

Average rainfall in December
Lynn, MA

Average rainfall in December - Lynn, MA
  • Average rainfall in December: 2.99"

The wettest month (with the highest rainfall) is December (2.99").
The driest month (with the least rainfall) is September (1.42").

Average rainfall days in December
Lynn, MA

Average rainfall days in December - Lynn, MA
  • Average rainfall days in December: 10.3 days

The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is January (7.1 days).

Average snowfall in December
Lynn, MA

Average snowfall in December - Lynn, MA
  • Average snowfall in December: 3.43"

The month with the highest snowfall is February (4.61").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Lynn, MA

Average snowfall days in December - Lynn, MA
  • Average snowfall days in December: 5.3 days

The months with the highest number of snowfall days are January and February (7.7 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average sea temperature in December
Lynn, MA

Average sea temperature in December - Lynn, 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).

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

Average daylight in December / Average sunshine in December - Lynn, 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 24min).
The months with the least sunshine are February and December (Average sunshine: 4h and 36min).

Average sunshine days in December
Lynn, MA

Average sunshine days in December - Lynn, MA
  • Average sunshine days in December: 16.1 days

The month with the most sunshine days is January (17.8 days).
The month with the least sunshine days is April (13.2 days).

Average UV index in December
Lynn, MA

Average UV index in December - Lynn, 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
Lynn, MA

Average cloud cover in December - Lynn, MA
  • Average cloud cover in December: 49

The month with the most cloud cover is March (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in December
Lynn, MA

Average visibility in December - Lynn, 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).

Lynn, Massachusetts, USA

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