September Weather in Kelso, United States

Last updated: June 24, 2025

In September, the average temperature in Kelso, United States hovers around 23°C (74°F). Visitors can expect a range from a cool 8°C (47°F) to a sweltering 36°C (97°F). During this month, precipitation averages 72 mm (2.9 in) over approximately 7 days, and the humidity is notably high at 75%. Whether you're basking in the warmth or dodging the rain, there's something for everyone!

September Temperature in Kelso

In September in Kelso, the average temperature is 23°C (74°F). The maximum can reach 36°C (97°F) and the minimum can be as low as 8°C (47°F). This makes it an ideal destination for travelers seeking warm weather, but be prepared for cooler evenings.

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 23°C (74°F), with highs reaching up to 36°C (97°F) and lows dropping to around 8°C (47°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 72 mm (2.9 in) over the course of 7 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 72 mm (2.9 inches) of precipitation spread over approximately 7 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Kelso

In Kelso in September, humidity is 75%. With an average temperature of 23°C (74°F), this humidity feels like a warm, heavy blanket wrapping around you, making it feel more sweltering than it actually is, which can be quite uncomfortable for traveling.

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 75%, 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 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For 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 9, which falls under the very 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	2°C (37°F)	107 mm (4.2 inches)	86%	moderate
February Weather	4°C (40°F)	127 mm (5.0 inches)	84%	high
March Weather	10°C (50°F)	164 mm (6.5 inches)	84%	high
April Weather	14°C (57°F)	135 mm (5.3 inches)	80%	very high
May Weather	20°C (69°F)	158 mm (6.2 inches)	82%	extreme
June Weather	25°C (77°F)	102 mm (4.0 inches)	83%	extreme
July Weather	27°C (81°F)	96 mm (3.8 inches)	79%	very high
August Weather	25°C (78°F)	93 mm (3.6 inches)	76%	very high
September Weather	23°C (74°F)	72 mm (2.9 inches)	75%	very high
October Weather	16°C (61°F)	129 mm (5.1 inches)	74%	high
November Weather	8°C (46°F)	95 mm (3.7 inches)	85%	moderate
December Weather	6°C (42°F)	91 mm (3.6 inches)	88%	moderate