Last updated: June 24, 2025
In December, the average temperature in Iowa City, United States hovers around -1°C (31°F). While it can plummet to a chilling -22°C (-8°F), there's also the potential for warmer days reaching up to 22°C (72°F). Expect about 46 mm (1.8 in) of precipitation spread over 5 days, contributing to an average humidity of 84%. Prepare accordingly to experience the full range of December's weather!
In December in Iowa City, the average temperature is -1°C (31°F), with maximums reaching up to 22°C (72°F) and minimums dropping as low as -22°C (-8°F). This wide temperature range makes Iowa City an ideal destination for travelers seeking both cool winter adventures and milder spring outings.
In Iowa City in December, the precipitation amount is 46 mm (1.8 in) recorded over a span of 5 days.
In Iowa City in December humidity is 84%. With an average temperature of -1°C (31°F), this humidity feels like a biting chill that seeps through layers of clothing, making outdoor excursions brisk and invigorating, yet challenging for those unaccustomed to such damp conditions.
In Iowa City in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Iowa City, you can check the information here.
UV Risk Categories
Weather in Iowa City varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Iowa City, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (22°F) | 48 mm (1.9 inches) | 81% | moderate |
| February Weather | -4°C (24°F) | 58 mm (2.3 inches) | 81% | moderate |
| March Weather | 4°C (39°F) | 80 mm (3.2 inches) | 81% | high |
| April Weather | 9°C (49°F) | 84 mm (3.3 inches) | 82% | very high |
| May Weather | 17°C (62°F) | 139 mm (5.5 inches) | 78% | very high |
| June Weather | 23°C (74°F) | 128 mm (5.0 inches) | 81% | extreme |
| July Weather | 25°C (77°F) | 79 mm (3.1 inches) | 79% | very high |
| August Weather | 23°C (73°F) | 83 mm (3.3 inches) | 77% | very high |
| September Weather | 20°C (68°F) | 130 mm (5.1 inches) | 78% | very high |
| October Weather | 12°C (53°F) | 135 mm (5.3 inches) | 78% | high |
| November Weather | 3°C (38°F) | 50 mm (2.0 inches) | 87% | moderate |
| December Weather | -1°C (31°F) | 46 mm (1.8 inches) | 84% | moderate |