Last updated: June 24, 2025
In December, the average temperature in Ellensburg, United States hovers around -1°C (31°F), with a minimum dipping as low as -12°C (11°F) and a maximum reaching up to 15°C (60°F). Expect 72 mm (2.8 in) of precipitation over approximately 12 days, paired with a high average humidity of 88%. Be prepared for chilly and damp conditions!
In December, Ellensburg experiences an average temperature of -1°C (31°F), with maximums reaching 15°C (60°F) and minimums dipping as low as -12°C (11°F). Travelers should prepare for chilly conditions and pack layers to stay comfortable during their visit.
In Ellensburg in December, the total precipitation amount is 72 mm (2.8 in) over the course of 12 days.
In Ellensburg in December, humidity is 88%. With an average temperature of -1°C (31°F), this humidity feels like a biting cold that penetrates your clothing, making outdoor exploration challenging and the air clingy, adding an extra chill that can make you feel even colder than the temperature suggests.
In Ellensburg 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 Ellensburg, you can visit Hourly UV Index in Ellensburg.
UV Risk Categories
Weather in Ellensburg varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Ellensburg, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (29°F) | 75 mm (2.9 inches) | 86% | low |
| February Weather | -1°C (31°F) | 75 mm (3.0 inches) | 86% | moderate |
| March Weather | 3°C (38°F) | 44 mm (1.7 inches) | 87% | high |
| April Weather | 8°C (46°F) | 38 mm (1.5 inches) | 84% | high |
| May Weather | 13°C (56°F) | 23 mm (0.9 inches) | 81% | very high |
| June Weather | 17°C (63°F) | 13 mm (0.5 inches) | 82% | very high |
| July Weather | 21°C (70°F) | 1 mm (0.1 inches) | 79% | very high |
| August Weather | 21°C (69°F) | 5 mm (0.2 inches) | 63% | very high |
| September Weather | 15°C (60°F) | 24 mm (1.0 inches) | 62% | very high |
| October Weather | 8°C (46°F) | 53 mm (2.1 inches) | 83% | moderate |
| November Weather | 2°C (37°F) | 58 mm (2.3 inches) | 89% | moderate |
| December Weather | -1°C (31°F) | 72 mm (2.8 inches) | 88% | low |