September Weather in Eureka, United States

Last updated: June 24, 2025

The average temperature in Eureka, United States during September is a pleasant 22°C (72°F), with the mercury fluctuating between a minimum of 8°C (46°F) and a maximum of 35°C (95°F). Expect an average precipitation of 56 mm (2.2 in) spread over 7 days, with a comfortable average humidity of 76%. Enjoy the varied climate as you explore this vibrant destination!

September Temperature in Eureka

In September in Eureka, the average temperature is 22°C (72°F). Maximums can reach 35°C (95°F), and minimums can be as low as 8°C (46°F). This range makes it an ideal time for travelers to enjoy a mix of warm days and cooler evenings, perfect for exploring the area comfortably.

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

The chart illustrates September temperature patterns in Eureka, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Eureka, September typically has an average temperature of 22°C (72°F), with highs reaching up to 35°C (95°F) and lows dropping to around 8°C (46°F).

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

September Precipitation in Eureka

In Eureka in September, the total precipitation amount is 56 mm (2.2 in) over a period of 7 days.

September Precipitation Trends in Eureka

The chart displays monthly precipitation patterns in Eureka, 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 Eureka, September typically receives around 56 mm (2.2 inches) of precipitation spread over approximately 7 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 Eureka

In Eureka in September humidity is 76%. With an average temperature of 22°C (72°F), this humidity feels like a warm embrace, making travel slightly uncomfortable as you navigate through the thick, saturated air.

September Average Humidity in Eureka

This chart illustrates the average monthly humidity levels in Eureka, 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 Eureka is approximately 76%, 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 Eureka

In Eureka 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 Eureka.

Maximum UV Index Levels in Eureka for September

The chart shows the monthly maximum UV Index (UVI) for Eureka 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 Eureka typically reaches 9, which falls under the very high exposure category.

Data source: Eureka 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 Eureka Compares to Other Months

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

This table compares monthly weather conditions in Eureka, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	0°C (33°F)	75 mm (3.0 inches)	82%	moderate
February Weather	2°C (36°F)	81 mm (3.2 inches)	80%	moderate
March Weather	8°C (47°F)	129 mm (5.1 inches)	80%	high
April Weather	13°C (55°F)	124 mm (4.9 inches)	80%	very high
May Weather	19°C (67°F)	144 mm (5.7 inches)	82%	very high
June Weather	24°C (76°F)	88 mm (3.5 inches)	83%	extreme
July Weather	26°C (80°F)	95 mm (3.7 inches)	81%	very high
August Weather	24°C (76°F)	139 mm (5.5 inches)	80%	very high
September Weather	22°C (72°F)	56 mm (2.2 inches)	76%	very high
October Weather	15°C (59°F)	110 mm (4.3 inches)	76%	high
November Weather	7°C (45°F)	70 mm (2.8 inches)	85%	moderate
December Weather	4°C (40°F)	57 mm (2.2 inches)	86%	moderate