Last updated: June 24, 2025
In December, the average temperature in Glen Ellyn, United States is a crisp 0°C (33°F). Expect a minimum drop to -21°C (-5°F), while the maximum can reach a balmy 19°C (67°F). Throughout the month, anticipate about 53 mm (2.1 in) of precipitation spread over 7 days, alongside a high average humidity of 84%.
In December in Glen Ellyn, the average temperature is 0°C (33°F). Maximum temperatures can reach 19°C (67°F), while minimums can drop as low as -21°C (-5°F). Be prepared for a wide range of temperatures if you plan to travel during this time.
In Glen Ellyn in December, the total precipitation amount is 53 mm (2.1 in) spread over a period of 7 days.
In Glen Ellyn in December humidity is 84%. With average temperature 0°C (33°F), this humidity feels like a damp chill that seeps into your bones, making outdoor adventures less enjoyable and travel plans challenging.
In Glen Ellyn in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Glen Ellyn, you can visit Hourly UV Index in Glen Ellyn.
UV Risk Categories
Weather in Glen Ellyn varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Glen Ellyn, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (26°F) | 61 mm (2.4 inches) | 82% | moderate |
| February Weather | -2°C (28°F) | 60 mm (2.4 inches) | 83% | moderate |
| March Weather | 4°C (39°F) | 79 mm (3.1 inches) | 84% | high |
| April Weather | 9°C (48°F) | 115 mm (4.5 inches) | 85% | very high |
| May Weather | 15°C (60°F) | 164 mm (6.4 inches) | 79% | very high |
| June Weather | 21°C (71°F) | 134 mm (5.3 inches) | 82% | very high |
| July Weather | 24°C (75°F) | 105 mm (4.1 inches) | 80% | very high |
| August Weather | 23°C (73°F) | 92 mm (3.6 inches) | 81% | very high |
| September Weather | 20°C (68°F) | 85 mm (3.3 inches) | 80% | very high |
| October Weather | 12°C (54°F) | 127 mm (5.0 inches) | 82% | high |
| November Weather | 4°C (39°F) | 55 mm (2.2 inches) | 88% | moderate |
| December Weather | 0°C (33°F) | 53 mm (2.1 inches) | 84% | low |