Last updated: June 24, 2025
In Grand Junction, United States, the average temperature in December hovers around -1°C (30°F). You can expect a chilly climate, with minimum temperatures plummeting to -23°C (-9°F) and peaks reaching as high as 22°C (72°F). A total precipitation of 37 mm (1.4 in) is spread over about 5 days, while the average humidity remains high at 83%, creating a crisp and refreshing atmosphere.
In December in Grand Junction, the average temperature is -1°C (30°F), with maximums reaching 22°C (72°F) and minimums dropping as low as -23°C (-9°F). This wide temperature range means visitors should be well-prepared for both chilly and mild weather while exploring.
In Grand Junction in December, the precipitation amount is 37 mm (1.4 in) spread over a duration of 5 days.
In Grand Junction in December humidity is 83%. With an average temperature of -1°C (30°F), this humidity feels like a biting chill that seeps through your layers, making outdoor activities uncomfortable and encouraging travelers to seek shelter indoors.
In Grand Junction 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 Grand Junction, you can check the information here.
UV Risk Categories
Weather in Grand Junction varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Grand Junction, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (22°F) | 32 mm (1.3 inches) | 78% | moderate |
| February Weather | -5°C (23°F) | 39 mm (1.5 inches) | 80% | moderate |
| March Weather | 4°C (39°F) | 76 mm (3.0 inches) | 77% | moderate |
| April Weather | 9°C (49°F) | 66 mm (2.6 inches) | 77% | very high |
| May Weather | 17°C (62°F) | 163 mm (6.4 inches) | 77% | very high |
| June Weather | 23°C (74°F) | 101 mm (4.0 inches) | 81% | extreme |
| July Weather | 25°C (77°F) | 84 mm (3.3 inches) | 81% | very high |
| August Weather | 23°C (74°F) | 90 mm (3.5 inches) | 77% | very high |
| September Weather | 20°C (68°F) | 108 mm (4.2 inches) | 73% | very high |
| October Weather | 11°C (52°F) | 122 mm (4.8 inches) | 75% | high |
| November Weather | 3°C (38°F) | 36 mm (1.4 inches) | 85% | moderate |
| December Weather | -1°C (30°F) | 37 mm (1.4 inches) | 83% | moderate |