Temperature in Illinois in December

Daytime highs, nighttime lows and the warmest cities in Illinois, the United States of America this December.

Illinois, the United States of America, a region in the United States of America, experiences maximum daytime temperatures in December ranging from 1°C (34°F) in Galena to 9°C (48°F) in Metropolis. Nighttime temperatures generally drop to -1°C (30°F) in Metropolis and -8°C (18°F) in Galena. December falls during the winter season.

What is the temperature of the different cities in Illinois, the United States of America in December?

Explore the map below to discover average December temperatures at the top destinations in Illinois. For a deeper dive, simply click on any destination dot.

Select a Month

Check the conditions for any month of the year.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

For a detailed overview over the year and the best time to visit Illinois, check out our Illinois's climate page.

See also: Illinois weather by month.

Best Places to Visit in Illinois in December

Click on a destination dot for more details. Toggle the map to compare temperatures or precipitation across Illinois.

Conditions Temperatures Precipitation
Avg daytime high -5°C (23°F) cold → 32°C (90°F) hot

Marker color shows the average daytime high temperature in December: blue is cold, red is hot.

See all December weather averages, cities and regions in Illinois

Illinois temperatures in December: frequently asked questions

How hot does it get in Illinois, the United States of America in December?

Average daytime highs in Illinois, the United States of America during December reach about 3°C (37°F) in Chicago.

How cold does it get at night in Illinois, the United States of America in December?

Average overnight lows in Illinois, the United States of America during December sit near -5°C (23°F) in Chicago.

What is the warmest city in December in Illinois, the United States of America?

Metropolis tops the warmest city list in our database with average maximum daytime temperatures around 9°C (48°F) and a minimum nighttime temperature of around -1°C (30°F).

What is the coldest city in December in Illinois, the United States of America?

According to our data, Galena holds the title for the coldest city in Illinois, the United States of America in December. It experiences maximum temperatures of approximately 1°C (34°F) and drops to lows of about -8°C (18°F) during the night.

How much sun does Illinois, the United States of America get in December?

Most cities enjoy a balanced amount of sunshine, with around 107 hours of sunlight anticipated in Chicago. This ensures the days are neither too dim nor excessively sunny.

Interested in more climate information?

We have much more information about the climate in Illinois.

Weather and climate has detailed information for every country in the world. Are you going to the United States of America? Get detailed historical weather averages for many cities in the United States of America.

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