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
Altamont, Illinois, experiences a temperature shift at the start of December, with average high-temperatures adjusting from a cool 51.4°F (10.8°C) in November to a wintry 40.6°F (4.8°C). Nighttime temperature experiences an average drop to a subzero cold 29.3°F (-1.5°C) in December.Humidity
In Altamont, the average relative humidity in December is 78%.Rainfall
In December, the rain falls for 8.6 days. Throughout December, 1.77" (45mm) of precipitation is accumulated. Throughout the year, there are 141.3 rainfall days, and 26.77" (680mm) of precipitation is accumulated.Snowfall
January through March, November and December are months with snowfall in Altamont. In Altamont, in December, during 3.7 snowfall days, 1.81" (46mm) of snow is typically accumulated. In Altamont, during the entire year, snow falls for 17.7 days and aggregates up to 6.73" (171mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of the month, sunrise is at 6:55 am and sunset at 4:32 pm. On the last day of December, in Altamont, sunrise is at 7:13 am and sunset at 4:42 pm CST.
Sunshine
In Altamont, the average sunshine in December is 4.6h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Altamont. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for the average person.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Opt for tightly woven and loose clothing to enhance protection from the Sun. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
How many days does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Altamont have in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Altamont have in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Altamont, IL
- Average high temperature in December: 40.6°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in December: 29.3°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in December
Altamont, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Altamont, IL
- Average wind speed in December: 9.4mph
The windiest months (with the highest average wind speed) are January and February (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in December
Altamont, IL
- Average humidity in December: 78%
The months with the highest relative humidity are July and August (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Altamont, IL
- Average rainfall in December: 1.77"
The wettest month (with the highest rainfall) is April (3.35").
The driest month (with the least rainfall) is February (1.38").
Average rainfall days in December
Altamont, IL
- Average rainfall days in December: 8.6 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in December
Altamont, IL
- Average snowfall in December: 1.81"
The month with the highest snowfall is January (2.01").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Altamont, IL
- Average snowfall days in December: 3.7 days
The month with the highest number of snowfall days is January (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Altamont, IL
- Average daylight in December: 9h and 3min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in December
Altamont, IL
- Average sunshine days in December: 19.5 days
The month with the most sunshine days is December (19.5 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in December
Altamont, IL
- 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, November and December (UV index 2).
Average cloud cover in December
Altamont, IL
- Average cloud cover in December: 51
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June and September (Cloud cover 29).
Average visibility in December
Altamont, IL
- 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).
Altamont, Illinois, USA
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