Last updated: June 24, 2025
In December, the average temperature in Grantsville, United States hovers around -1°C (31°F). Expect chilly extremes with minimums dipping to -15°C (4°F), while highs can reach 15°C (59°F). Throughout the month, anticipate 36 mm (1.4 in) of precipitation over 8 days, contributing to an average humidity of 84%. Stay prepared for a brisk and damp atmosphere!
If you're planning to visit Grantsville in December, be prepared for chilly weather, with average temperatures hovering around -1°C (31°F) and possible extremes ranging from -15°C (4°F) to a mild 15°C (59°F).
In Grantsville in December, the precipitation amount is 36 mm (1.4 in) over a period of 8 days.
In Grantsville 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 Grantsville 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 Grantsville, you can check the information here.
UV Risk Categories
Weather in Grantsville varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Grantsville, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -1°C (31°F) | 40 mm (1.6 inches) | 85% | moderate |
| February Weather | 1°C (34°F) | 47 mm (1.8 inches) | 86% | moderate |
| March Weather | 6°C (43°F) | 61 mm (2.4 inches) | 79% | high |
| April Weather | 10°C (50°F) | 56 mm (2.2 inches) | 71% | very high |
| May Weather | 15°C (60°F) | 49 mm (1.9 inches) | 59% | extreme |
| June Weather | 23°C (73°F) | 14 mm (0.5 inches) | 55% | extreme |
| July Weather | 27°C (81°F) | 16 mm (0.6 inches) | 44% | extreme |
| August Weather | 26°C (78°F) | 18 mm (0.7 inches) | 34% | extreme |
| September Weather | 20°C (68°F) | 31 mm (1.2 inches) | 42% | very high |
| October Weather | 10°C (51°F) | 33 mm (1.3 inches) | 63% | high |
| November Weather | 5°C (41°F) | 27 mm (1.1 inches) | 81% | moderate |
| December Weather | -1°C (31°F) | 36 mm (1.4 inches) | 84% | moderate |