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
The beginning of December brings a minor change in the average high-temperature, shifting from a fresh 52°F (11.1°C) in November to a chilly 43.9°F (6.6°C). An average temperature of 36.9°F (2.7°C) is logged during the nights of December in Islip, a small step down from daytime highs.Humidity
The average relative humidity in December in Islip, New York, is 74%.Rainfall
In Islip, during December, the rain falls for 11.6 days and regularly aggregates up to 3.58" (91mm) of precipitation. In Islip, New York, during the entire year, the rain falls for 153.2 days and collects up to 34.45" (875mm) of precipitation.Snowfall
Months with snowfall in Islip are January through March, October through December. In Islip, in December, snow falls for 1.7 days, with typically accumulated 1.42" (36mm) of snow. In Islip, New York, during the entire year, snow falls for 13 days and aggregates up to 5.87" (149mm) of snow.Ocean temperature
In December, the average ocean temperature in Islip is 48.9°F (9.4°C).Note: Diving into 48.9°F (9.4°C) when it's under 50°F (10°C) can cause immediate cold shock symptoms, marked by hyperventilation.
Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year in Islip, New York.On the first day of the month, sunrise is at 6:58 am and sunset at 4:26 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:35 pm EST.
Sunshine
In Islip, 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 value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.Note: A typical high UV index of 2 in December suggests the following recommendations:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Stay sun-safe with clothing that is both closely woven and worn loosely. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold in Islip?
What is the average humidity in December in Islip?
How many days does it rain in December in Islip?
How much does it snow in Islip in December?
What is the ocean temperature in December in Islip?
What is the month with the shortest days in Islip?
What is the average length of the day in December in Islip?
When are sunrise and sunset in December in Islip?
How long on average sun shines in December in Islip?
What is the month with the lowest UV index in Islip?
How high is the UV index in December in Islip?
Average temperature in December
Islip, NY
- Average high temperature in December: 43.9°F
The warmest month (with the highest average high temperature) is July (79°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in December: 36.9°F
The month with the highest average low temperature is August (72°F).
The coldest month (with the lowest average low temperature) is January (30°F).
Average pressure in December
Islip, 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
Islip, NY
- Average wind speed in December: 12.9mph
The windiest month (with the highest average wind speed) is January (13.4mph).
The calmest month (with the lowest average wind speed) is July (8.6mph).
Average humidity in December
Islip, NY
- Average humidity in December: 74%
The months with the highest relative humidity are May and June (77%).
The month with the lowest relative humidity is November (71%).
Average rainfall in December
Islip, NY
- Average rainfall in December: 3.58"
The wettest month (with the highest rainfall) is July (3.86").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in December
Islip, NY
- Average rainfall days in December: 11.6 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (7.6 days).
Average snowfall in December
Islip, NY
- Average snowfall in December: 1.42"
The month with the highest snowfall is March (1.97").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in December
Islip, NY
- Average snowfall days in December: 1.7 days
The month with the highest number of snowfall days is February (4.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average sea temperature in December
Islip, NY
- Average sea temperature in December: 49°F
The best month for swimming (with the highest average sea temperature) is August (74°F).
The coldest month (with the lowest average sea temperature) is February (39.7°F).
Average daylight in December /
Average sunshine in December
Islip, NY
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
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
Islip, NY
- Average sunshine days in December: 17.4 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is July (11.2 days).
Average UV index in December
Islip, 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
Islip, 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
Islip, 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).
Islip, New York, USA
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