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
December's arrival aligns with a minor decrease in average high-temperatures, from November's cool 52.3°F (11.3°C) to a chilly 44.1°F (6.7°C). Holtsville's nighttime temperatures in December display a slight drop from daytime highs, averaging to an icy 37.2°F (2.9°C).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. In Holtsville, during the entire year, snow falls for 14.7 days and aggregates up to 6.14" (156mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 6:57 am and sunset at 4:25 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:34 pm EST.
Sunshine
The average sunshine in December in Holtsville is 4.9h.UV index
The months with the lowest UV index are January through March and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the average person.Note: The daily high UV index of 2 during December translates into the following recommendations:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Frequently asked questions
How cold does it get in Holtsville in December?
What is the average humidity in December in Holtsville?
What is the rainiest month in Holtsville?
How much does it rain in Holtsville in December?
When does it start to snow in Holtsville?
What is the month with the shortest days in Holtsville?
How many hours of daylight does Holtsville have in December?
What time are sunrise and sunset in December in Holtsville?
How many hours of sunshine does Holtsville have in December?
What is the month with the lowest UV index in Holtsville?
How high is the UV index in December in Holtsville?
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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