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
A mild shift in the average high-temperature occurs in December, reducing from a fresh 52.3°F (11.3°C) in November to a frosty 44.1°F (6.7°C). Holtsville's nights throughout December are marked by an average low temperature of 37.2°F (2.9°C), a minor drop from the day's high.Humidity
In Holtsville, the average relative humidity in December is 74%.Rainfall
December is the month with the most rainfall. Rain falls for 12.3 days and accumulates 3.74" (95mm) of precipitation.Snowfall
January through March, May, October and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 2.4 snowfall days, it receives 1.22" (31mm) of snow. Throughout the year, there are 14.7 snowfall days, and 6.14" (156mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 18min of daylight.On the first day of December in Holtsville, sunrise is at 6:57 am and sunset at 4:25 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:34 pm EST.
Sunshine
In Holtsville, the average sunshine in December is 4.9h.UV index
January through March and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for the average person.Note: The daily maximum UV index of 2 in December interprets into the following advice:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
What is the wettest month?
How much does it rain in December?
When does it start to snow?
What is the month with the shortest days?
How many hours of daylight does Holtsville have in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Holtsville, NY
- Average high temperature in December: 44.1°F
The warmest month (with the highest average high temperature) is August (78.1°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in December: 37.2°F
The month with the highest average low temperature is August (71.8°F).
The coldest month (with the lowest average low temperature) is January (30.2°F).
Average pressure in December
Holtsville, NY
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Holtsville, NY
- Average wind speed in December: 13.4mph
The windiest month (with the highest average wind speed) is January (13.8mph).
The calmest months (with the lowest average wind speed) are July and August (9mph).
Average humidity in December
Holtsville, NY
- Average humidity in December: 74%
The months with the highest relative humidity are May and June (78%).
The month with the lowest relative humidity is November (71%).
Average rainfall in December
Holtsville, NY
- Average rainfall in December: 3.74"
The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is January (2.17").
Average rainfall days in December
Holtsville, NY
- Average rainfall days in December: 12.3 days
The month with the highest number of rainy days is July (17.7 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in December
Holtsville, NY
- Average snowfall in December: 1.22"
The month with the highest snowfall is March (2.13").
The months with the least snowfall are April, June, July, August, September and November (0").
Average snowfall days in December
Holtsville, NY
- Average snowfall days in December: 2.4 days
The month with the highest number of snowfall days is February (4.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Holtsville, NY
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Holtsville, NY
- Average sunshine days in December: 16.9 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is July (11.3 days).
Average UV index in December
Holtsville, NY
- 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 and December (UV index 2).
Average cloud cover in December
Holtsville, NY
- Average cloud cover in December: 48
The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Holtsville, NY
- 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).
Holtsville, New York, USA
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