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
Setting in of December comes with a decrease in the average high-temperature, moving from a fresh 52.9°F (11.6°C) in November to a chilly 43.9°F (6.6°C). Alton sees an average low-temperature of 31.8°F (-0.1°C) during December.Humidity
February and December, with an average relative humidity of 80%, are the most humid months.Rainfall
In Alton, in December, during 11.3 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. Throughout the year, there are 160 rainfall days, and 29.45" (748mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, September through December. In Alton, in December, snow falls for 5.5 days, with typically accumulated 1.14" (29mm) of snow. In Alton, during the entire year, snow falls for 26.8 days and aggregates up to 7.91" (201mm) of snow.Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year in Alton.On the first day of the month, sunrise is at 7:43 am and sunset at 5:26 pm. On the last day of December, sunrise is at 8:01 am and sunset at 5:36 pm EST.
Sunshine
With an average of 4.4h of sunshine, December has the least sunshine of the year.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: In December, the maximum UV index of 2 translates into these guidelines:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold does it get in December?
What are the most humid months?
What is the average humidity in December?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days in Alton?
What is the average length of the day in December?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What is the month with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Alton, IN
- Average high temperature in December: 43.9°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in December: 31.8°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 (25.7°F).
Average pressure in December
Alton, IN
- 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 (29.95"Hg).
Average wind speed in December
Alton, IN
- Average wind speed in December: 7.1mph
The windiest months (with the highest average wind speed) are January and February (7.7mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in December
Alton, IN
- Average humidity in December: 80%
The months with the highest relative humidity are February and December (80%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Alton, IN
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is April (3.31").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in December
Alton, IN
- Average rainfall days in December: 11.3 days
The month with the highest number of rainy days is May (18.7 days).
The month with the least rainy days is November (9.8 days).
Average snowfall in December
Alton, IN
- Average snowfall in December: 1.14"
The month with the highest snowfall is January (2.24").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in December
Alton, IN
- Average snowfall days in December: 5.5 days
The month with the highest number of snowfall days is January (7.6 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Alton, IN
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 24min).
Average sunshine days in December
Alton, IN
- Average sunshine days in December: 15.2 days
The month with the most sunshine days is October (19.1 days).
The month with the least sunshine days is May (11.1 days).
Average UV index in December
Alton, IN
- Average UV index in December: 2
The months with the highest UV index are May, 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
Alton, IN
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in December
Alton, IN
- Average visibility in December: 5mi
The months with the highest visibility are March, April, June, August, October and November (6mi).
The months with the lowest visibility are January, February, May, July, September and December (5mi).
Alton, Indiana, USA
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