December weather forecast and climate
Williston, NY

December, the first month of the winter, in Williston, is also a wintry month, with average temperature ranging between max 34.9°F (1.6°C) and min 26.2°F (-3.2°C).

Temperature

In December, the average high-temperature decreases, from a frosty 45.5°F (7.5°C) in November, to a cold 34.9°F (1.6°C). The average low-temperature, in Williston, is 26.2°F (-3.2°C).

Humidity

In December, the average relative humidity in Williston is 85%.

Rainfall

In Williston, during December, the rain falls for 10 days and regularly aggregates up to 1.65" (42mm) of precipitation. In Williston, New York, during the entire year, the rain falls for 161.8 days and collects up to 21.93" (557mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In Williston, snow falls for 15.8 days, with typically accumulated 4.41" (112mm) of snow. In Williston, during the entire year, snow falls for 78.6 days, and aggregates up to 25.24" (641mm) of snow.

Daylight

The month with the shortest days in Williston is December, with an average of 9.1h of daylight.

Sunshine

In Williston, the average sunshine is 2.7h.

UV index

Months with the lowest UV index in Williston are January and December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a low threat to health from the exposure to the Sun's UV rays for the average person.
Note: The daily maximum UV index of 1 interpret into the following advice:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. 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 Williston?

The average high-temperature, in December, is 34.9°F (1.6°C), while the average low-temperature is 26.2°F (-3.2°C).

What is the average humidity in December in Williston?

The average relative humidity in December in Williston is 85%.

How many days does it rain in December in Williston?

In Williston, New York, in December, it is raining for 10 days, with typically 1.65" (42mm) of accumulated precipitation.

How much does it snow in Williston in December?

In Williston, New York, in December, snow falls for 15.8 days, with typically accumulated 4.41" (112mm) of snow.

What is the month with the shortest days in Williston?

The month with the shortest days is December, with an average of 9.1h of daylight.

How many hours of daylight does Williston have in December?

In Williston, the average length of the day in December is 9.1h.

How many hours of sunshine does Williston have in December?

The average sunshine in December in Williston, New York, is 2.7h.

What is the month with the lowest UV index in Williston?

January and December, with an average maximum UV index of 1, are months with the lowest UV index in Williston.

What is the UV index reading in December in Williston?

In December, the average daily maximum UV index in Williston is 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from the exposure to the Sun's UV radiation.
Average temperature in December - Williston, NY
  • Average high temperature in December: 1.6°C

The warmest month (with the highest average high temperature) is July (26.2°C).
The month with the lowest average high temperature is January (-1.7°C).

  • Average low temperature in December: -3.2°C

The month with the highest average low temperature is July (16.1°C).
The coldest month (with the lowest average low temperature) is January (-7.7°C).

Average pressure in December - Williston, NY
  • Average pressure in December: 1018mbar

The month with the highest atmospheric pressure is November (1018.9mbar).
The month with the lowest atmospheric pressure is June (1013.4mbar).

Average wind speed in December - Williston, NY
  • Average wind speed in December: 15km/h

The windiest month (with the highest average wind speed) is January (16.6km/h).
The calmest month (with the lowest average wind speed) is July (10.3km/h).

Average humidity in December - Williston, NY
  • Average humidity in December: 85%

Months with the highest relative humidity are January and February (87%).
Months with the lowest relative humidity are May, July and August (77%).

Average rainfall in December - Williston, NY
  • Average rainfall in December: 42mm

The wettest month (with the highest rainfall) is May (62mm).
The driest month (with the least rainfall) is September (34mm).

Average rainfall days in December - Williston, NY
  • Average rainfall days in December: 10 days

The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is February (6.8 days).

Average snowfall in December - Williston, NY
  • Average snowfall in December: 112mm

The month with the highest snowfall is February (168mm).
Months with the least snowfall are June, July, August and September (0mm).

Average snowfall days in December - Williston, NY
  • Average snowfall days in December: 15.8 days

The month with the highest number of snowfall days is January (19 days).
Months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December / Average sunshine in December - Williston, NY
  • Average daylight in December: 9.1h

The month with the longest days is June (Average daylight: 15.3h).
The month with the shortest days is December (Average daylight: 9.1h).

  • Average sunshine in December: 2.7h

The month with the most sunshine is July (Average sunshine: 10.3h).
The month with the least sunshine is January (Average sunshine: 2.3h).

Average sunshine days in December - Williston, NY
  • Average sunshine days in December: 8.2 days

The month with the most sunshine days is June (13.4 days).
The month with the least sunshine days is February (6.7 days).

Average UV index in December - Williston, NY
  • Average UV index in December: 1

The month with the highest UV index is July (UV index 6).
Months with the lowest UV index are January and December (UV index 1).

Average cloud cover in December - Williston, NY
  • Average cloud cover in December: 72

The month with the most cloud cover is January (Cloud cover 78).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in December - Williston, NY
  • Average visibility in December: 8km

Months with the highest visibility are April, May, June, July, August, September, October and November (9km).
Months with the lowest visibility are January, February, March and December (8km).