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 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
The onset of December introduces a moderate change in Sullivan's weather, with average high-temperatures falling from November's chilly 44.4°F (6.9°C) to a cold 33.4°F (0.8°C). Sullivan reports a consistent average low-temperature of 22.8°F (-5.1°C) throughout December nights.Humidity
In Sullivan, the average relative humidity in December is 82%.Rainfall
In Sullivan, New Hampshire, in December, it is raining for 7.7 days, with typically 0.87" (22mm) of accumulated precipitation. Throughout the year, there are 125.1 rainfall days, and 11.69" (297mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Sullivan, in December, snow falls for 7.4 days, with typically accumulated 1.61" (41mm) of snow. In Sullivan, during the entire year, snow falls for 39.8 days and aggregates up to 10.2" (259mm) 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 7:01 am and sunset at 4:15 pm. On the last day of December, sunrise is at 7:20 am and sunset at 4:24 pm EST.
Sunshine
In December, the average sunshine is 4.8h.UV index
January through March, October through 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 low health risk from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 2 during December leads to these instructions:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Mind this! Nearly twice the UV radiation from the Sun can be reflected by the snow.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December in Sullivan?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Sullivan have in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Sullivan have in December?
What are the months with the lowest UV index?
How high is the UV index in December in Sullivan?
Average temperature in December
Sullivan, NH
- Average high temperature in December: 33.4°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in December: 22.8°F
The month with the highest average low temperature is July (58.6°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).
Average pressure in December
Sullivan, NH
- Average pressure in December: 30.04"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Sullivan, NH
- Average wind speed in December: 7.3mph
The windiest months (with the highest average wind speed) are January, February and March (7.9mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in December
Sullivan, NH
- Average humidity in December: 82%
The month with the highest relative humidity is February (85%).
The month with the lowest relative humidity is April (74%).
Average rainfall in December
Sullivan, NH
- Average rainfall in December: 0.87"
The wettest month (with the highest rainfall) is July (1.3").
The driest month (with the least rainfall) is March (0.75").
Average rainfall days in December
Sullivan, NH
- Average rainfall days in December: 7.7 days
The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in December
Sullivan, NH
- Average snowfall in December: 1.61"
The month with the highest snowfall is January (2.64").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Sullivan, NH
- Average snowfall days in December: 7.4 days
The month with the highest number of snowfall days is February (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Sullivan, NH
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
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 18min).
The month with the least sunshine is February (Average sunshine: 4h and 24min).
Average sunshine days in December
Sullivan, NH
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (13.8 days).
Average UV index in December
Sullivan, NH
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
Sullivan, NH
- Average cloud cover in December: 49
The months with the most cloud cover are February and March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 35).
Average visibility in December
Sullivan, NH
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
Sullivan, New Hampshire, USA
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