Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average sea temperature in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December's onset introduces a mild reduction in the average high-temperature, from a cool 51.3°F (10.7°C) in November to a frosty 44.4°F (6.9°C). In Harwich Port, nights during December observe an average temperature decrease to a cold 37.6°F (3.1°C).Humidity
In Harwich Port, the average relative humidity in December is 75%.Rainfall
In December, the rain falls for 11.2 days. Throughout December, 2.05" (52mm) of precipitation is accumulated. In Harwich Port, during the entire year, the rain falls for 142.4 days and collects up to 22.09" (561mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. In Harwich Port, in December, during 4.7 snowfall days, 0.67" (17mm) of snow is typically accumulated. In Harwich Port, during the entire year, snow falls for 20.8 days and aggregates up to 4.37" (111mm) of snow.Ocean temperature
In Harwich Port, the average seawater temperature in December is 46°F (7.8°C).Note: Unprotected swimming in 46°F (7.8°C) is dangerous due to potential cold shock. Especially when temperatures go below 50°F (10°C), leading to hyperventilation.
Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:48 am and sunset at 4:10 pm. On the last day of December, sunrise is at 7:07 am and sunset at 4:20 pm EST.
Sunshine
With an average of 4.3h of sunshine, December has the least sunshine of the year.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Harwich Port. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 2 in December interprets into the following advice:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Opt for tightly woven and loose clothing to enhance protection from the Sun. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What is the average humidity in December?
How many days does it rain in December?
How much does it snow in December?
What is the ocean temperature in December?
What is the month with the shortest days?
How many hours of daylight does Harwich Port have in December?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Harwich Port, MA
- Average high temperature in December: 44.4°F
The warmest month (with the highest average high temperature) is August (71.6°F).
The months with the lowest average high temperature are January and February (39°F).
- Average low temperature in December: 37.6°F
The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (31.6°F).
Average pressure in December
Harwich Port, MA
- Average pressure in December: 30.02"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).
Average wind speed in December
Harwich Port, MA
- Average wind speed in December: 17.5mph
The windiest month (with the highest average wind speed) is January (18mph).
The calmest month (with the lowest average wind speed) is August (11.4mph).
Average humidity in December
Harwich Port, MA
- Average humidity in December: 75%
The months with the highest relative humidity are June and July (85%).
The month with the lowest relative humidity is November (74%).
Average rainfall in December
Harwich Port, MA
- Average rainfall in December: 2.05"
The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is November (1.46").
Average rainfall days in December
Harwich Port, MA
- Average rainfall days in December: 11.2 days
The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is February (8.3 days).
Average snowfall in December
Harwich Port, MA
- Average snowfall in December: 0.67"
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Harwich Port, MA
- Average snowfall days in December: 4.7 days
The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in December
Harwich Port, MA
- Average sea temperature in December: 46.1°F
The best month for swimming (with the highest average sea temperature) is August (67.5°F).
The coldest month (with the lowest average sea temperature) is March (39°F).
Average daylight in December /
Average sunshine in December
Harwich Port, 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 12min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days in December
Harwich Port, MA
- Average sunshine days in December: 13.6 days
The month with the most sunshine days is August (17.6 days).
The month with the least sunshine days is January (13 days).
Average UV index in December
Harwich Port, MA
- Average UV index in December: 2
The months with the highest UV index are 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
Harwich Port, MA
- Average cloud cover in December: 54
The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Harwich Port, 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).
Harwich Port, Massachusetts, USA
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