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
December weather is marked by a drop in the average high-temperature, falling from a chilly 46.8°F (8.2°C) in November to a cold 34.3°F (1.3°C). During the nights in December, Rock Island observes an average low-temperature of 23.7°F (-4.6°C).Humidity
The average relative humidity in December in Rock Island is 81%.Rainfall
In December, in Rock Island, the rain falls for 6.9 days. Throughout December, 1.26" (32mm) of precipitation is accumulated. In Rock Island, during the entire year, the rain falls for 138.1 days and collects up to 27.32" (694mm) of precipitation.Snowfall
January through April, October through December are months with snowfall in Rock Island. In Rock Island, in December, during 6.9 snowfall days, 1.89" (48mm) of snow is typically accumulated. In Rock Island, during the entire year, snow falls for 35.5 days and aggregates up to 12.8" (325mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of December in Rock Island, Illinois, sunrise is at 7:09 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 4:42 pm CST.
Sunshine
In Rock Island, the average sunshine in December is 4.2h.UV index
In Rock Island, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 2 in December leads to these recommendations:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Frequently asked questions
How cold is it in Rock Island in December?
What is the average humidity in December in Rock Island?
How many days does it rain in December in Rock Island?
How much does it snow in Rock Island in December?
What is the month with the shortest days in Rock Island?
How many hours of daylight does Rock Island have in December?
What time are sunrise and sunset in December in Rock Island?
How long on average sun shines in December in Rock Island?
What is the UV index intensity in December in Rock Island?
Average temperature in December
Rock Island, IL
- Average high temperature in December: 34.3°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28°F).
- Average low temperature in December: 23.7°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (15.6°F).
Average pressure in December
Rock Island, IL
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in December
Rock Island, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in December
Rock Island, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Rock Island, IL
- Average rainfall in December: 1.26"
The wettest month (with the highest rainfall) is May (4.49").
The driest month (with the least rainfall) is February (1.1").
Average rainfall days in December
Rock Island, IL
- Average rainfall days in December: 6.9 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (4.3 days).
Average snowfall in December
Rock Island, IL
- Average snowfall in December: 1.89"
The month with the highest snowfall is January (3.98").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Rock Island, IL
- Average snowfall days in December: 6.9 days
The month with the highest number of snowfall days is January (10.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rock Island, IL
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in December
Rock Island, IL
- Average sunshine days in December: 17.8 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (11.4 days).
Average UV index in December
Rock Island, IL
- Average UV index in December: 2
The months with the highest UV index are July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Rock Island, IL
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in December
Rock Island, 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).
Rock Island, Illinois, USA
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