December weather forecast and climate
West Islip, NY

The first month of the winter, December, is also a frosty month in West Islip, New York, with average temperature varying between 44.1°F (6.7°C) and 36.9°F (2.7°C).

Temperature

In West Islip, New York, the average high-temperature in December marginally drops, from a fresh 52.2°F (11.2°C) in November, to a chilly 44.1°F (6.7°C). In December, the average low-temperature is 36.9°F (2.7°C).

Humidity

In West Islip, New York, the average relative humidity in December is 74%.

Rainfall

In December, in West Islip, the rain falls for 12.3 days. Throughout December, 3.78" (96mm) of precipitation is accumulated. Throughout the year, there are 157 rainfall days, and 35.98" (914mm) of precipitation is accumulated.

Snowfall

Months with snowfall in West Islip, New York, are January through April, October through December. In West Islip, snow falls for 2.4 days, with typically accumulated 1.34" (34mm) of snow. Throughout the year, there are 14.4 snowfall days, and 6.06" (154mm) of snow is accumulated.

Daylight

The month with the shortest days in West Islip is December, with an average of 9.3h of daylight.

Sunshine

In December, the average sunshine in West Islip is 5h.

UV index

Months with the lowest UV index in West Islip are January through March and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The daily maximum UV index of 2 in December interpret into the following advice:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in December in West Islip?

In West Islip, in December, the average high-temperature is 44.1°F (6.7°C), and the average low-temperature is 36.9°F (2.7°C).

What is the average humidity in December in West Islip?

In December, the average relative humidity in West Islip, New York, is 74%.

How many days does it rain in December in West Islip?

In December, the rain falls for 12.3 days. Throughout December, 3.78" (96mm) of precipitation is accumulated.

How much does it snow in West Islip in December?

In West Islip, New York, in December, snow falls for 2.4 days, with typically accumulated 1.34" (34mm) of snow.

What is the month with the shortest days in West Islip?

December has the shortest days of the year, with an average of 9.3h of daylight.

How many hours of daylight does West Islip have in December?

The average length of the day in December is 9.3h.

How many hours of sunshine does West Islip have in December?

In December, the average sunshine in West Islip is 5h.

What is the month with the lowest UV index in West Islip?

Months with the lowest UV index in West Islip, New York, are January through March and December, with an average maximum UV index of 2.

What is the UV index reading in December in West Islip?

In West Islip, New York, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health threat from the exposure to the Sun's UV rays.
Average temperature in December - West Islip, NY
  • Average high temperature in December: 44.1°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

Months with the highest average low temperature are July and August (72°F).
The coldest month (with the lowest average low temperature) is January (30.4°F).

Average pressure in December - West Islip, NY
  • Average pressure in December: 30.06"

The month with the highest atmospheric pressure is November (30.09").
The month with the lowest atmospheric pressure is June (29.93").

Average wind speed in December - West Islip, NY
  • Average wind speed in December: 13.1mph

The windiest month (with the highest average wind speed) is January (13.6mph).
The calmest month (with the lowest average wind speed) is July (8.9mph).

Average humidity in December - West Islip, NY
  • Average humidity in December: 74%

The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is November (71%).

Average rainfall in December - West Islip, NY
  • Average rainfall in December: 3.78"

The wettest month (with the highest rainfall) is July (3.98").
The driest month (with the least rainfall) is January (2.2").

Average rainfall days in December - West Islip, NY
  • Average rainfall days in December: 12.3 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is January (8.1 days).

Average snowfall in December - West Islip, NY
  • Average snowfall in December: 1.34"

The month with the highest snowfall is March (2.17").
Months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December - West Islip, NY
  • Average snowfall days in December: 2.4 days

The month with the highest number of snowfall days is February (4.2 days).
Months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December / Average sunshine in December - West Islip, NY
  • Average daylight in December: 9.3h

The month with the longest days is June (Average daylight: 15.1h).
The month with the shortest days is December (Average daylight: 9.3h).

  • Average sunshine in December: 5h

The month with the most sunshine is July (Average sunshine: 10.8h).
The month with the least sunshine is February (Average sunshine: 4.8h).

Average sunshine days in December - West Islip, NY
  • Average sunshine days in December: 16.4 days

The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is July (11.4 days).

Average UV index in December - West Islip, NY
  • Average UV index in December: 2

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January, February, March and December (UV index 2).

Average cloud cover in December - West 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 - West Islip, NY
  • Average visibility in December: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).