January Weather in Rainier, United States

Last updated: June 24, 2025

In January, the average temperature in Rainier, United States hovers around 5°C (41°F), with a minimum dipping as low as -9°C (16°F) and a maximum reaching 14°C (57°F). Expect a fair amount of rain as well, with total precipitation averaging 183 mm (7.2 in) over 17 days. It's also worth noting that humidity is typically high, averaging 85%, creating a chilly and damp atmosphere.

January Temperature in Rainier

In January in Rainier, the average temperature is 5°C (41°F). The maximum can reach 14°C (57°F), and the minimum can be as low as -9°C (16°F). Pack warm clothing and be prepared for chilly conditions while exploring this destination.

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

The chart illustrates January temperature patterns in Rainier, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rainier, January typically has an average temperature of 5°C (41°F), with highs reaching up to 14°C (57°F) and lows dropping to around -9°C (16°F).

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

January Precipitation in Rainier

In Rainier in January, the total precipitation amount is 183 mm (7.2 in), occurring over the course of 17 days.

January Precipitation Trends in Rainier

The chart displays monthly precipitation patterns in Rainier, 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 Rainier, January typically receives around 183 mm (7.2 inches) of precipitation spread over approximately 17 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 Rainier

In Rainier in January, humidity is 85%. With an average temperature of 5°C (41°F), this humidity feels like a damp chill that seeps into your bones, making outdoor exploration a challenge as the cold air clings to your skin.

January Average Humidity in Rainier

This chart illustrates the average monthly humidity levels in Rainier, 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 Rainier is approximately 85%, 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 Rainier

In Rainier 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 Rainier, you can visit Hourly UV Index in Rainier.

Maximum UV Index Levels in Rainier for January

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

Data source: Rainier 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 Rainier Compares to Other Months

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

This table compares monthly weather conditions in Rainier, 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)	183 mm (7.2 inches)	85%	low
February Weather	4°C (40°F)	166 mm (6.5 inches)	84%	moderate
March Weather	7°C (45°F)	145 mm (5.7 inches)	85%	moderate
April Weather	10°C (50°F)	119 mm (4.7 inches)	83%	high
May Weather	13°C (56°F)	71 mm (2.8 inches)	83%	very high
June Weather	16°C (61°F)	59 mm (2.3 inches)	83%	very high
July Weather	18°C (65°F)	9 mm (0.4 inches)	82%	very high
August Weather	19°C (66°F)	9 mm (0.4 inches)	74%	very high
September Weather	16°C (62°F)	79 mm (3.1 inches)	71%	high
October Weather	11°C (51°F)	117 mm (4.6 inches)	81%	moderate
November Weather	7°C (45°F)	172 mm (6.8 inches)	87%	moderate
December Weather	5°C (40°F)	192 mm (7.6 inches)	87%	low