December weather forecastRockport, IL
December
Weather in December
December, the first month of the winter in Rockport, is also an icy month, with temperature in the range of an average high of 40.5°F (4.7°C) and an average low of 28.2°F (-2.1°C).Temperature
The onset of December coincides with a reduction in the average high-temperature, falling from a cool 51.6°F (10.9°C) in November to a cold 40.5°F (4.7°C). Rockport records a consistent low-temperature of 28.2°F (-2.1°C) during December nights.Humidity
In December, the average relative humidity is 77%.Rainfall
In Rockport, during December, the rain falls for 7.6 days and regularly aggregates up to 1.5" (38mm) of precipitation. Throughout the year, there are 142.7 rainfall days, and 27.64" (702mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall. In Rockport, in December, snow falls for 4.5 days, with typically accumulated 1.38" (35mm) of snow. In Rockport, during the entire year, snow falls for 26.1 days and aggregates up to 9.45" (240mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:06 am and sunset at 4:40 pm. On the last day of December, in Rockport, sunrise is at 7:24 am and sunset at 4:50 pm CST.
Sunshine
In Rockport, the average sunshine in December is 4.8h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for the ordinary person.Note: The maximum UV index, 2 during December, leads to the following recommendations:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rockport, IL
- Average high temperature in December: 40.5°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (34.9°F).
- Average low temperature in December: 28.2°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 (22.1°F).
Average pressure in December
Rockport, IL
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Rockport, IL
- Average wind speed in December: 9.3mph
The windiest months (with the highest average wind speed) are January and February (9.7mph).
The calmest month (with the lowest average wind speed) is July (6mph).
Average humidity in December
Rockport, IL
- Average humidity in December: 77%
The month with the highest relative humidity is May (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Rockport, IL
- Average rainfall in December: 1.5"
The wettest month (with the highest rainfall) is May (3.5").
The driest month (with the least rainfall) is February (1.46").
Average rainfall days in December
Rockport, IL
- Average rainfall days in December: 7.6 days
The month with the highest number of rainy days is May (17.3 days).
The months with the least rainy days are January and February (6.3 days).
Average snowfall in December
Rockport, IL
- Average snowfall in December: 1.38"
The month with the highest snowfall is January (3.03").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Rockport, IL
- Average snowfall days in December: 4.5 days
The month with the highest number of snowfall days is January (8.5 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
Rockport, IL
- Average daylight in December: 9h and 24min
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 24min).
- Average sunshine in December: 4h and 48min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The months with the least sunshine are January and February (Average sunshine: 4h and 30min).
Average sunshine days in December
Rockport, IL
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is December (19.2 days).
The month with the least sunshine days is June (10.9 days).
Average UV index in December
Rockport, 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
Rockport, IL
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 30).
Average visibility in December
Rockport, 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).





