January Weather in Washington, United States

Last updated: June 24, 2025

In January, the average temperature in Washington, United States hovers around 9°C (48°F), with a range that can dip to a chilling -8°C (19°F) at its lowest and peak at a comfortable 25°C (78°F). Expect around 100 mm (3.9 in) of precipitation spread across 9 days, contributing to a notably high average humidity of 86%. Whether you enjoy crisp air or the occasional refreshing rain, this month offers a unique blend of weather experiences!

January Temperature in Washington

In January in Washington, the average temperature is 9°C (48°F). Maximums can reach 25°C (78°F), while minimums can drop as low as -8°C (19°F). Be prepared for a wide range of temperatures, making it a perfect time to explore both outdoor activities and cozy indoor attractions.

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 9°C (48°F), with highs reaching up to 25°C (78°F) and lows dropping to around -8°C (19°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 100 mm (3.9 in) spread over 9 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 100 mm (3.9 inches) of precipitation spread over approximately 9 days.

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

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Millimeters (mm) Inches (in)

January Humidity in Washington

In Washington in January, humidity is 86%. With an average temperature of 9°C (48°F), this humidity feels like a damp chill that wraps around you, making outdoor activities uncomfortable and travel less enjoyable.

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 86%, 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 reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Washington for better planning.

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 4, 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	9°C (48°F)	100 mm (3.9 inches)	86%	moderate
February Weather	12°C (53°F)	117 mm (4.6 inches)	84%	high
March Weather	14°C (58°F)	87 mm (3.4 inches)	83%	very high
April Weather	18°C (65°F)	107 mm (4.2 inches)	81%	very high
May Weather	23°C (73°F)	109 mm (4.3 inches)	81%	extreme
June Weather	26°C (79°F)	97 mm (3.8 inches)	81%	extreme
July Weather	27°C (82°F)	105 mm (4.1 inches)	83%	extreme
August Weather	27°C (81°F)	125 mm (4.9 inches)	81%	very high
September Weather	25°C (77°F)	98 mm (3.9 inches)	82%	very high
October Weather	20°C (68°F)	112 mm (4.4 inches)	78%	very high
November Weather	12°C (54°F)	82 mm (3.2 inches)	86%	high
December Weather	10°C (50°F)	117 mm (4.6 inches)	89%	moderate