Last updated: June 24, 2025
In December, the average temperature in Washington, United States hovers around 4°C (39°F). Expect a chilly range, with minimums dropping to -14°C (8°F) and maximums reaching up to 19°C (67°F). This month also brings 117 mm (4.6 in) of precipitation over 11 days, contributing to an average humidity level of 86%. Bundle up and embrace the seasonal vibes!
In December in Washington, the average temperature is 4°C (39°F), with maximums reaching 19°C (67°F) and minimums dropping as low as -14°C (8°F). Travelers should be prepared for a range of temperatures, making layered clothing essential for comfort during their visit.
In Washington in December, the total precipitation amount reaches 117 mm (4.6 in) over the course of 11 days.
In Washington in December humidity is 86%. With an average temperature of 4°C (39°F), this humidity feels like a chilly mist enveloping you, making it essential to bundle up while exploring, as each breath comes with a damp chill that can be quite refreshing yet starkly invigorating for travelers.
In Washington 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 Washington, you can check the information here.
UV Risk Categories
Weather in Washington varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Washington, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | 1°C (34°F) | 91 mm (3.6 inches) | 88% | moderate |
February Weather | 4°C (39°F) | 125 mm (4.9 inches) | 88% | moderate |
March Weather | 7°C (46°F) | 115 mm (4.5 inches) | 88% | high |
April Weather | 12°C (55°F) | 143 mm (5.6 inches) | 86% | very high |
May Weather | 18°C (65°F) | 147 mm (5.8 inches) | 82% | very high |
June Weather | 22°C (72°F) | 153 mm (6.0 inches) | 84% | very high |
July Weather | 25°C (77°F) | 112 mm (4.4 inches) | 82% | very high |
August Weather | 24°C (75°F) | 123 mm (4.8 inches) | 73% | very high |
September Weather | 21°C (70°F) | 104 mm (4.1 inches) | 73% | very high |
October Weather | 15°C (60°F) | 113 mm (4.4 inches) | 81% | high |
November Weather | 7°C (45°F) | 82 mm (3.2 inches) | 89% | moderate |
December Weather | 4°C (39°F) | 117 mm (4.6 inches) | 86% | moderate |