January Weather in Washington, United States

Last updated: June 24, 2025

In January, the average temperature in Washington, United States hovers around -1°C (30°F). However, temperatures can swing dramatically, with minimums reaching as low as -25°C (-12°F) and maximums peaking at 18°C (64°F). Expect 28 mm (1.1 in) of precipitation spread over about 5 days, while humidity stays relatively high at 76%.

January Temperature in Washington

In January in Washington, the average temperature is -1°C (30°F). Maximums can reach 18°C (64°F), while minimums can drop as low as -25°C (-12°F). Be prepared for a wide range of temperatures when traveling here!

January Weather in Washington: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Washington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Washington, January typically has an average temperature of -1°C (30°F), with highs reaching up to 18°C (64°F) and lows dropping to around -25°C (-12°F).

Data source: Temperature data for Washington generated using information from the Copernicus Climate Change Service.

January Precipitation in Washington

In Washington in January, the precipitation amount is 28 mm (1.1 in) over a period of 5 days.

January Precipitation Trends in Washington

The chart displays monthly precipitation patterns in Washington, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Washington, January typically receives around 28 mm (1.1 inches) of precipitation spread over approximately 5 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Washington

In Washington in January, humidity is 76%. With an average temperature of -1°C (30°F), this humidity feels like a biting chill that penetrates your layers, making outdoor activities less enjoyable and prompting travelers to seek warmth and shelter more often than not.

January Average Humidity in Washington

This chart illustrates the average monthly humidity levels in Washington, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Washington is approximately 76%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Washington

In Washington in January, 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.

Maximum UV Index Levels in Washington for January

The chart shows the monthly maximum UV Index (UVI) for Washington in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Washington typically reaches 3, which falls under the moderate exposure category.

Data source: Washington January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How January Weather in Washington Compares to Other Months

Weather in Washington varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Washington, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Washington, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-1°C (30°F)	28 mm (1.1 inches)	76%	moderate
February Weather	-1°C (30°F)	27 mm (1.1 inches)	77%	moderate
March Weather	7°C (45°F)	86 mm (3.4 inches)	70%	high
April Weather	12°C (53°F)	60 mm (2.4 inches)	73%	very high
May Weather	18°C (65°F)	201 mm (7.9 inches)	82%	very high
June Weather	25°C (78°F)	94 mm (3.7 inches)	82%	extreme
July Weather	27°C (81°F)	89 mm (3.5 inches)	81%	extreme
August Weather	25°C (77°F)	95 mm (3.7 inches)	78%	very high
September Weather	22°C (72°F)	67 mm (2.7 inches)	71%	very high
October Weather	13°C (55°F)	121 mm (4.8 inches)	71%	high
November Weather	6°C (43°F)	31 mm (1.2 inches)	81%	moderate
December Weather	2°C (35°F)	28 mm (1.1 inches)	84%	moderate