Last updated: June 24, 2025
In Helena Valley West Central, United States, the average temperature in December hovers around -4°C (25°F), with extremes ranging from a chilly -25°C (-12°F) to a warm 17°C (63°F). Expect about 30 mm (1.2 in) of precipitation over 8 days, and prepare for a high average humidity of 90%. Stay cozy and enjoy the serene winter ambiance!
In December in Helena Valley West Central, the average temperature is -4°C (25°F), with maximums reaching 17°C (63°F) and minimums dropping as low as -25°C (-12°F). It's essential to pack for a wide range of temperatures and be prepared for cold weather while traveling during this time.
In Helena Valley West Central in December, the precipitation amount is 30 mm (1.2 in) over the course of 8 days.
In Helena Valley West Central in December humidity is 90%. With an average temperature of -4°C (25°F), this humidity feels like a dense, icy blanket wrapping around you, making travel feel particularly stifling in the cold despite the sub-zero temperatures.
In Helena Valley West Central 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 Helena Valley West Central, you can visit Hourly UV Index in Helena Valley West Central.
UV Risk Categories
Weather in Helena Valley West Central varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Helena Valley West Central, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (22°F) | 19 mm (0.7 inches) | 87% | moderate |
| February Weather | -8°C (18°F) | 44 mm (1.7 inches) | 88% | moderate |
| March Weather | -1°C (31°F) | 30 mm (1.2 inches) | 83% | high |
| April Weather | 4°C (39°F) | 59 mm (2.3 inches) | 78% | very high |
| May Weather | 10°C (51°F) | 64 mm (2.5 inches) | 76% | very high |
| June Weather | 16°C (60°F) | 78 mm (3.1 inches) | 78% | very high |
| July Weather | 21°C (69°F) | 17 mm (0.7 inches) | 77% | very high |
| August Weather | 20°C (67°F) | 23 mm (0.9 inches) | 71% | very high |
| September Weather | 14°C (57°F) | 37 mm (1.5 inches) | 68% | very high |
| October Weather | 5°C (41°F) | 35 mm (1.4 inches) | 72% | moderate |
| November Weather | 0°C (32°F) | 29 mm (1.1 inches) | 84% | moderate |
| December Weather | -4°C (25°F) | 30 mm (1.2 inches) | 90% | low |