Climate averages 1991–2020
Iowa City weather
in December.
A cold month with moderate precipitation: the 10th warmest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Iowa City: daytime highs average 1.4°C and nights cool to about -6.3°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 49 mm of precipitation on roughly 7 days, which makes December a month with moderate precipitation (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 13 min on an average December day.
The nearest other city in this atlas is Cedar Rapids (40 km away). In December its highs average 0.7°C, 0.7°C cooler than Iowa City, with 46 mm of precipitation.
Among the 498 cities listed in the United States, Iowa City ranks 478th of 498 for the warmest December highs and joint 132nd of 498 for the driest December (precipitation, lowest first). The mean December high of those 498 cities is 10.5°C; Iowa City is 9.1°C cooler than that mean.
From December to January, average highs fall by 2.9°C to -1.5°C, and monthly precipitation falls from 49 mm to 39 mm.
The annual picture
December in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Iowa City climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -1.5°C-10.3°C | -10.3°C | 39 | 7.1 | 9.510 h |
| February | 1.1°C-8.2°C | -8.2°C | 46 | 6.5 | 10.611 h |
| March | 8.7°C-1.7°C | -1.7°C | 69 | 9.1 | 11.912 h |
| April | 15.5°C4.9°C | 4.9°C | 111 | 11.8 | 13.313 h |
| May | 21.4°C11.4°C | 11.4°C | 123 | 13.4 | 14.515 h |
| June | 26.3°C17.0°C | 17.0°C | 128 | 11.7 | 15.115 h |
| July | 28.2°C19.3°C | 19.3°C | 95 | 9.5 | 14.915 h |
| August | 27.4°C18.4°C | 18.4°C | 96 | 9.1 | 13.914 h |
| September | 23.7°C14.2°C | 14.2°C | 99 | 8.1 | 12.513 h |
| October | 16.6°C7.6°C | 7.6°C | 74 | 8.6 | 11.111 h |
| November | 8.7°C0.3°C | 0.3°C | 59 | 7.6 | 9.910 h |
| December, selected | 1.4°C-6.3°C | -6.3°C | 49 | 6.9 | 9.29 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Cedar Rapids in DecemberUnited States · 40 kmHigh 0.7°C · Low -7.1°C · 46 mm precipitation
- Davenport in DecemberUnited States · 81 kmHigh 1.9°C · Low -5.4°C · 53 mm precipitation
- Des Moines in DecemberUnited States · 173 kmHigh 1.5°C · Low -6.5°C · 41 mm precipitation
- Peoria (Illinois), United States in DecemberUnited States · 195 kmHigh 3.3°C · Low -4.0°C · 57 mm rain
- Rockford in DecemberUnited States · 213 kmHigh 1.1°C · Low -6.0°C · 53 mm precipitation
- Madison in DecemberUnited States · 235 kmHigh -0.1°C · Low -7.4°C · 48 mm precipitation
- Bloomington (Illinois), United States in DecemberUnited States · 250 kmHigh 3.3°C · Low -4.1°C · 59 mm rain
- Springfield (Illinois), United States in DecemberUnited States · 261 kmHigh 4.4°C · Low -3.1°C · 59 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Iowa City) is explained once on the Iowa City year overview and on the Sources, method and limits page.