December weather forecastChatham, NH
December
Weather in December
December, the first month of the winter in Chatham, is still a freezing cold month, with an average temperature varying between 29.8°F (-1.2°C) and 18.9°F (-7.3°C).Temperature
The arrival of December signals a shift in temperature, down from an icy 40.8°F (4.9°C) in November to a freezing cold 29.8°F (-1.2°C). Nightly temperatures in Chatham, New Hampshire, drop to an average low of 18.9°F (-7.3°C) in December.Humidity
The average relative humidity in December in Chatham, New Hampshire, is 82%.Rainfall
In Chatham, during December, the rain falls for 12.7 days and regularly aggregates up to 1.57" (40mm) of precipitation. Throughout the year, in Chatham, there are 158 rainfall days, and 18.58" (472mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Chatham, in December, snow falls for 11.6 days, with typically accumulated 4.09" (104mm) of snow. In Chatham, during the entire year, snow falls for 64.6 days and aggregates up to 25.31" (643mm) of snow.Daylight
December has the shortest days of the year in Chatham, with an average of 8h and 54min of daylight.On the first day of the month, sunrise is at 6:59 am and sunset at 4:06 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:15 pm EST.
Sunshine
In Chatham, New Hampshire, the average sunshine in December is 4.7h.UV index
January through April, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Chatham, New Hampshire. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for average individuals.Note: A maximum UV index of 2 in December 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. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Chatham, NH
- Average high temperature in December: 29.8°F
The warmest month (with the highest average high temperature) is July (76.8°F).
The month with the lowest average high temperature is January (24.4°F).
- Average low temperature in December: 18.9°F
The month with the highest average low temperature is July (55.8°F).
The coldest month (with the lowest average low temperature) is January (10.4°F).
Average pressure in December
Chatham, NH
- 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 (29.91"Hg).
Average wind speed in December
Chatham, NH
- Average wind speed in December: 6.2mph
The windiest month (with the highest average wind speed) is January (6.8mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in December
Chatham, NH
- Average humidity in December: 82%
The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are May and November (77%).
Average rainfall in December
Chatham, NH
- Average rainfall in December: 1.57"
The wettest months (with the highest rainfall) are April and October (2.17").
The driest month (with the least rainfall) is September (0.94").
Average rainfall days in December
Chatham, NH
- Average rainfall days in December: 12.7 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (9.8 days).
Average snowfall in December
Chatham, NH
- Average snowfall in December: 4.09"
The month with the highest snowfall is February (6.73").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Chatham, NH
- Average snowfall days in December: 11.6 days
The months with the highest number of snowfall days are January and February (14.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Chatham, NH
- Average daylight in December: 8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 4h and 42min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in December
Chatham, NH
- Average sunshine days in December: 12.7 days
The month with the most sunshine days is September (16.5 days).
The month with the least sunshine days is April (10.1 days).
Average UV index in December
Chatham, NH
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in December
Chatham, NH
- Average cloud cover in December: 51
The month with the most cloud cover is February (Cloud cover 53).
The months with the least cloud cover are August and September (Cloud cover 37).
Average visibility in December
Chatham, NH
- Average visibility in December: 5mi
The months with the highest visibility are April, May, June, July, August, October, November and December (5mi).
The months with the lowest visibility are January, February, March and September (4mi).
