Kelso (WA) Weather & Climate: Best Time to Visit

The climate in Kelso is known for significant temperature differences throughout the year, making the weather dynamic. Typically, average maximum daytime temperatures range from a comfortable 26°C (79°F) in August to a chilly 7°C (45°F) in the coolest month, December.

Nights vary from 12°C (54°F) in August to around 1°C (34°F) during the colder months.

Check out our detailed temperature page for more information.

Temperature ranges by month

Kelso has a notably wet climate with abundant precipitation, recording 1254 mm (49 in) of rain/snowfall per year. The climate in Kelso shows significant variation throughout the year. Expect heavy rainfall in December, the wettest month, with an average of 200 mm (7.9 in) of precipitation over 23 rainy days.

In contrast, the driest month July offers drier and sunnier days, with around 13 mm (0.5 in) of rainfall over 5 rainy days. For more details, please visit our Kelso Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

For those who appreciate different seasons, Kelso serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 11.1 hours of sunshine daily, and embrace the darker days in December, offering only 2.1 hours of daily sunlight.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

The relative humidity is high throughout the year in Kelso.

The city experiences its highest humidity in December, reaching 83%. In July, the humidity drops to its lowest level at 63%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year