September Weather in Sumner, United States

Last updated: June 24, 2025

In Sumner, United States, the average temperature in September hovers around 22°C (73°F), creating a pleasant atmosphere. However, temperatures can vary significantly, with a minimum of 8°C (47°F) and a maximum of 34°C (94°F). Expect 70 mm (2.7 in) of precipitation spread over 7 days, contributing to an average humidity level of 79%.

September Temperature in Sumner

In September in Sumner, the average temperature is 22°C (73°F), with maximums reaching 34°C (94°F) and minimums dropping as low as 8°C (47°F). This is an ideal time for travelers looking to enjoy a warm climate while still having cooler evenings to explore the local sights comfortably.

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

The chart illustrates September temperature patterns in Sumner, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sumner, September typically has an average temperature of 22°C (73°F), with highs reaching up to 34°C (94°F) and lows dropping to around 8°C (47°F).

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

September Precipitation in Sumner

In Sumner in September, the precipitation amount is 70 mm (2.7 in) over a period of 7 days.

September Precipitation Trends in Sumner

The chart displays monthly precipitation patterns in Sumner, 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 Sumner, September typically receives around 70 mm (2.7 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 Sumner

In Sumner in September, humidity is 79%. With an average temperature of 22°C (73°F), this humidity feels like a warm, muggy embrace that makes outdoor activities feel more taxing, and a quick stroll can leave you feeling slightly sticky and ready for a refreshing break.

September Average Humidity in Sumner

This chart illustrates the average monthly humidity levels in Sumner, 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 Sumner is approximately 79%, 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 Sumner

In Sumner 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 Sumner.

Maximum UV Index Levels in Sumner for September

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

Data source: Sumner 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 Sumner Compares to Other Months

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

This table compares monthly weather conditions in Sumner, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	1°C (33°F)	91 mm (3.6 inches)	84%	moderate
February Weather	2°C (37°F)	107 mm (4.2 inches)	82%	moderate
March Weather	8°C (47°F)	133 mm (5.2 inches)	84%	high
April Weather	13°C (56°F)	120 mm (4.7 inches)	83%	very high
May Weather	20°C (68°F)	133 mm (5.3 inches)	80%	very high
June Weather	25°C (77°F)	112 mm (4.4 inches)	83%	extreme
July Weather	26°C (80°F)	97 mm (3.8 inches)	82%	very high
August Weather	25°C (77°F)	92 mm (3.6 inches)	82%	very high
September Weather	22°C (73°F)	70 mm (2.7 inches)	79%	very high
October Weather	16°C (60°F)	100 mm (3.9 inches)	79%	high
November Weather	7°C (44°F)	102 mm (4.0 inches)	88%	moderate
December Weather	4°C (39°F)	95 mm (3.7 inches)	87%	moderate