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
Arrival of December comes with a reduction in the average high-temperature, falling from a frosty 43.7°F (6.5°C) in November to an icy 33.3°F (0.7°C). McLean, during December nights, observes an average temperature of 23.9°F (-4.5°C).Humidity
In McLean, the average relative humidity in December is 87%.Rainfall
In December, in McLean, the rain falls for 9.5 days. Throughout December, 2.64" (67mm) of precipitation is accumulated. In McLean, New York, during the entire year, the rain falls for 165.9 days and collects up to 34.41" (874mm) of precipitation.Snowfall
January through May, October through December are months with snowfall in McLean, New York. In McLean, in December, snow falls for 16.4 days, with typically accumulated 7.87" (200mm) of snow. Throughout the year, in McLean, there are 87.1 snowfall days, and 39.17" (995mm) of snow is accumulated.Daylight
With an average of 9h and 6min of daylight, December has the shortest days of the year.On the first day of December in McLean, sunrise is at 7:15 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 4:42 pm EST.
Sunshine
In McLean, New York, the average sunshine in December is 2.8h.UV index
The months with the lowest UV index are January, February 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 unsafe exposure to UV radiation for average individuals.Note: An average maximum UV index of 1 in December leads to these recommendations:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. 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. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December in McLean?
What is the average humidity in December in McLean?
How many days does it rain in December in McLean?
How much does it snow in McLean in December?
What is the month with the shortest days in McLean?
How many hours of daylight does McLean have in December?
When are sunrise and sunset in December in McLean?
How many hours of sunshine does McLean have in December?
When is the lowest UV index in McLean?
What is the UV index reading in December in McLean?
Average temperature in December
McLean, NY
- Average high temperature in December: 33.3°F
The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is January (27.3°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is July (57.4°F).
The coldest month (with the lowest average low temperature) is January (16°F).
Average pressure in December
McLean, NY
- Average pressure in December: 30.07"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
McLean, NY
- Average wind speed in December: 9.6mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in December
McLean, NY
- Average humidity in December: 87%
The month with the highest relative humidity is February (88%).
The months with the lowest relative humidity are April, May and July (80%).
Average rainfall in December
McLean, NY
- Average rainfall in December: 2.64"
The wettest month (with the highest rainfall) is June (3.46").
The driest month (with the least rainfall) is January (2.24").
Average rainfall days in December
McLean, NY
- Average rainfall days in December: 9.5 days
The month with the highest number of rainy days is July (18.3 days).
The month with the least rainy days is January (6.7 days).
Average snowfall in December
McLean, NY
- Average snowfall in December: 7.87"
The month with the highest snowfall is February (9.17").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
McLean, NY
- Average snowfall days in December: 16.4 days
The month with the highest number of snowfall days is January (20.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
McLean, NY
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 2h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 2h and 24min).
Average sunshine days in December
McLean, NY
- Average sunshine days in December: 8.2 days
The month with the most sunshine days is September (13.8 days).
The month with the least sunshine days is February (5.1 days).
Average UV index in December
McLean, NY
- Average UV index in December: 1
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in December
McLean, NY
- Average cloud cover in December: 72
The month with the most cloud cover is February (Cloud cover 76).
The months with the least cloud cover are July and August (Cloud cover 38).
Average visibility in December
McLean, NY
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January and February (4mi).
McLean, New York, USA
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