December weather forecastIslip Terrace, NY
December
Weather in December
December, the first month of the winter in Islip Terrace, is also a frosty month, with an average temperature varying between 43.9°F (6.6°C) and 36.9°F (2.7°C).Temperature
In Islip Terrace, entering December brings a subtle temperature decrement, reducing from November's cool 52°F (11.1°C) to a chilly 43.9°F (6.6°C). In December, Islip Terrace experiences a marginal drop in temperature, with averages of 36.9°F (2.7°C) at night.Humidity
In December, the average relative humidity in Islip Terrace is 74%.Rainfall
In Islip Terrace, in December, during 11.6 rainfall days, 3.58" (91mm) of precipitation is typically accumulated. Throughout the year, in Islip Terrace, there are 153.2 rainfall days, and 34.45" (875mm) of precipitation is accumulated.Snowfall
January through March, October through December are months with snowfall. In Islip Terrace, in December, snow falls for 1.7 days, with typically accumulated 1.42" (36mm) of snow. In Islip Terrace, New York, during the entire year, snow falls for 13 days and aggregates up to 5.87" (149mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year in Islip Terrace.On the first day of December in Islip Terrace, sunrise is at 6:58 am and sunset at 4:25 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:35 pm EST.
Sunshine
In Islip Terrace, New York, 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 in Islip Terrace. A UV Index reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the average person.Note: In December, the maximum UV index of 2 transforms into these recommendations:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Islip Terrace, 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 Terrace, 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 Terrace, 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 Terrace, 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 Terrace, 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 Terrace, 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 Terrace, 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 Terrace, 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 daylight in December /
Average sunshine in December
Islip Terrace, NY
- Average daylight in December: 9h and 18min
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 54min
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 Terrace, 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 Terrace, 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 Terrace, 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 Terrace, 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).





