January Weather in Sammamish, United States

Last updated: June 24, 2025

In January, the average temperature in Sammamish, United States hovers around 5°C (41°F), with a minimum dipping to -12°C (11°F) and a maximum reaching 15°C (59°F). Expect 215 mm (8.5 in) of precipitation spread over 16 days, creating a humid atmosphere with an average humidity of 86%.

January Temperature in Sammamish

In January in Sammamish, the average temperature is 5°C (41°F). Maximums can reach 15°C (59°F) and minimums can be as low as -12°C (11°F). Travelers should prepare for a mix of chilly days and milder conditions, making it essential to pack layers for comfort.

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

The chart illustrates January temperature patterns in Sammamish, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sammamish, January typically has an average temperature of 5°C (41°F), with highs reaching up to 15°C (59°F) and lows dropping to around -12°C (11°F).

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

January Precipitation in Sammamish

In Sammamish in January, the precipitation amount is 215 mm (8.5 in) over the course of 16 days.

January Precipitation Trends in Sammamish

The chart displays monthly precipitation patterns in Sammamish, 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 Sammamish, January typically receives around 215 mm (8.5 inches) of precipitation spread over approximately 16 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 Sammamish

In Sammamish in January humidity is 86%. With an average temperature of 5°C (41°F), this humidity feels like a heavy, damp blanket wrapping around you, making outdoor activities uncomfortable and travel quite challenging due to the chill combined with the stickiness in the air.

January Average Humidity in Sammamish

This chart illustrates the average monthly humidity levels in Sammamish, 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 Sammamish 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 Sammamish

In Sammamish in January, 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 Sammamish, you can visit Hourly UV Index in Sammamish.

Maximum UV Index Levels in Sammamish for January

The chart shows the monthly maximum UV Index (UVI) for Sammamish 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 Sammamish typically reaches 2, which falls under the low exposure category.

Data source: Sammamish 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 Sammamish Compares to Other Months

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

This table compares monthly weather conditions in Sammamish, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	5°C (41°F)	215 mm (8.5 inches)	86%	low
February Weather	4°C (39°F)	242 mm (9.5 inches)	86%	moderate
March Weather	7°C (44°F)	167 mm (6.6 inches)	87%	moderate
April Weather	9°C (49°F)	154 mm (6.1 inches)	84%	high
May Weather	13°C (56°F)	94 mm (3.7 inches)	81%	very high
June Weather	16°C (60°F)	88 mm (3.5 inches)	82%	very high
July Weather	18°C (65°F)	33 mm (1.3 inches)	79%	very high
August Weather	18°C (65°F)	27 mm (1.0 inches)	63%	very high
September Weather	15°C (60°F)	124 mm (4.9 inches)	62%	high
October Weather	10°C (50°F)	220 mm (8.7 inches)	83%	moderate
November Weather	7°C (45°F)	238 mm (9.4 inches)	89%	low
December Weather	4°C (40°F)	248 mm (9.8 inches)	88%	low