January Weather in Lake Oswego, United States

Last updated: June 24, 2025

In Lake Oswego, United States, the average temperature in January hovers around 5°C (42°F), with a minimum drop to -14°C (7°F) and a possible maximum reach of 15°C (59°F). During this month, expect 163 mm (6.4 in) of precipitation spread across 17 days, contributing to a high average humidity of 85%. Stay prepared for a mix of chilly weather and rainy days!

January Temperature in Lake Oswego

In January in Lake Oswego, the average temperature is 5°C (42°F). The maximum can reach 15°C (59°F) and the minimum can be as low as -14°C (7°F). Travelers should be prepared for a wide range of temperatures, packing both warm clothing for chilly days and layers for warmer afternoons.

January Weather in Lake Oswego: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Lake Oswego, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lake Oswego, January typically has an average temperature of 5°C (42°F), with highs reaching up to 15°C (59°F) and lows dropping to around -14°C (7°F).

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

January Precipitation in Lake Oswego

In Lake Oswego in January, the precipitation amount is 163 mm (6.4 in) over the course of 17 days.

January Precipitation Trends in Lake Oswego

The chart displays monthly precipitation patterns in Lake Oswego, 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 Lake Oswego, January typically receives around 163 mm (6.4 inches) of precipitation spread over approximately 17 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 Lake Oswego

In Lake Oswego in January, humidity is 85%. With an average temperature of 5°C (42°F), this humidity feels like a damp chill that clings to your skin, making outdoor activities uncomfortable and requiring extra layers to stay warm while exploring.

January Average Humidity in Lake Oswego

This chart illustrates the average monthly humidity levels in Lake Oswego, 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 Lake Oswego 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 Lake Oswego

In Lake Oswego 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 Lake Oswego, you can visit Hourly UV Index in Lake Oswego.

Maximum UV Index Levels in Lake Oswego for January

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

Data source: Lake Oswego 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 Lake Oswego Compares to Other Months

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

This table compares monthly weather conditions in Lake Oswego, 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 (42°F)	163 mm (6.4 inches)	85%	low
February Weather	5°C (41°F)	172 mm (6.8 inches)	84%	moderate
March Weather	8°C (46°F)	135 mm (5.3 inches)	85%	moderate
April Weather	11°C (51°F)	117 mm (4.6 inches)	83%	high
May Weather	14°C (58°F)	58 mm (2.3 inches)	83%	very high
June Weather	18°C (64°F)	46 mm (1.8 inches)	83%	very high
July Weather	21°C (69°F)	6 mm (0.2 inches)	82%	very high
August Weather	21°C (70°F)	8 mm (0.3 inches)	74%	very high
September Weather	18°C (64°F)	62 mm (2.4 inches)	71%	high
October Weather	12°C (53°F)	105 mm (4.1 inches)	81%	moderate
November Weather	8°C (47°F)	155 mm (6.1 inches)	87%	moderate
December Weather	5°C (41°F)	183 mm (7.2 inches)	87%	low