September Weather in Kelso, United States

Last updated: June 24, 2025

In September, the average temperature in Kelso, United States is a pleasant 16°C (61°F), with a range that can dip to a minimum of 5°C (42°F) and soar to a maximum of 34°C (93°F). Expect about 84 mm (3.3 in) of precipitation over approximately 9 days, contributing to the average humidity of 74%. This combination creates a uniquely dynamic climate, perfect for a variety of outdoor activities!

September Temperature in Kelso

In September in Kelso, the average temperature is 16°C (61°F), with maximums reaching up to 34°C (93°F) and minimums dropping as low as 5°C (42°F). This makes it a great month for travelers to enjoy a mix of mild and warm weather while exploring the area's attractions.

September Weather in Kelso: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Kelso, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Kelso, September typically has an average temperature of 16°C (61°F), with highs reaching up to 34°C (93°F) and lows dropping to around 5°C (42°F).

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

September Precipitation in Kelso

In Kelso in September, the precipitation amount is 84 mm (3.3 in) spread over 9 days.

September Precipitation Trends in Kelso

The chart displays monthly precipitation patterns in Kelso, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Kelso, September typically receives around 84 mm (3.3 inches) of precipitation spread over approximately 9 days.

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

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Millimeters (mm) Inches (in)

September Humidity in Kelso

In Kelso in September humidity is 74%. With an average temperature of 16°C (61°F), this humidity feels like a damp blanket wrapping around you, making traveling quite uncomfortable as the air feels thick and muggy, potentially leading to fatigue and a longing for a cool breeze.

September Average Humidity in Kelso

This chart illustrates the average monthly humidity levels in Kelso, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Kelso is approximately 74%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Kelso

In Kelso in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Kelso.

Maximum UV Index Levels in Kelso for September

The chart shows the monthly maximum UV Index (UVI) for Kelso in September, 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 September, the maximum UV index in Kelso typically reaches 7, which falls under the high exposure category.

Data source: Kelso September 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 September Weather in Kelso Compares to Other Months

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

This table compares monthly weather conditions in Kelso, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	5°C (41°F)	190 mm (7.5 inches)	86%	low
February Weather	4°C (40°F)	175 mm (6.9 inches)	84%	moderate
March Weather	7°C (45°F)	150 mm (5.9 inches)	85%	moderate
April Weather	10°C (50°F)	125 mm (4.9 inches)	83%	high
May Weather	13°C (56°F)	74 mm (2.9 inches)	84%	very high
June Weather	16°C (61°F)	59 mm (2.3 inches)	84%	very high
July Weather	18°C (65°F)	10 mm (0.4 inches)	82%	very high
August Weather	19°C (66°F)	10 mm (0.4 inches)	73%	very high
September Weather	16°C (61°F)	84 mm (3.3 inches)	74%	high
October Weather	10°C (51°F)	132 mm (5.2 inches)	83%	moderate
November Weather	7°C (45°F)	179 mm (7.0 inches)	86%	moderate
December Weather	4°C (40°F)	202 mm (8.0 inches)	87%	low