September Weather in Saint Joseph, United States

Last updated: August 27, 2025

In September, the average temperature in Saint Joseph, United States hovers around 18°C (65°F). Expect a broad range, with minimum temperatures dipping to 4°C (39°F) and maximums peaking at 33°C (92°F). The month brings 108 mm (4.2 in) of precipitation over approximately 10 days, accompanied by a humidity level of 74%. Stay prepared for a mix of weather as you enjoy this vibrant destination!

September Temperature in Saint Joseph

In September in Saint Joseph, the average temperature is 18°C (65°F), with maximums reaching 33°C (92°F) and minimums dipping as low as 4°C (39°F). This diverse range of temperatures makes Saint Joseph an ideal destination for travelers seeking both warm sunny days and cooler evenings.

September Weather in Saint Joseph: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Saint Joseph, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint Joseph, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (92°F) and lows dropping to around 4°C (39°F).

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

September Precipitation in Saint Joseph

In Saint Joseph in September, the precipitation amount is 108 mm (4.2 in) distributed over a duration of 10 days.

September Precipitation Trends in Saint Joseph

The chart displays monthly precipitation patterns in Saint Joseph, 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 Saint Joseph, September typically receives around 108 mm (4.2 inches) of precipitation spread over approximately 10 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 Saint Joseph

In Saint Joseph in September humidity is 74%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace that can make even short walks feel laborious, leading travelers to seek shade and refreshment more often.

September Average Humidity in Saint Joseph

This chart illustrates the average monthly humidity levels in Saint Joseph, 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 Saint Joseph 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 Saint Joseph

In Saint Joseph in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Saint Joseph.

Maximum UV Index Levels in Saint Joseph for September

The chart shows the monthly maximum UV Index (UVI) for Saint Joseph 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 Saint Joseph typically reaches 8, which falls under the very high exposure category.

Data source: Saint Joseph 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 Saint Joseph Compares to Other Months

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

This table compares monthly weather conditions in Saint Joseph, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (20°F)	37 mm (1.5 inches)	84%	low
February Weather	-6°C (21°F)	52 mm (2.0 inches)	85%	moderate
March Weather	2°C (35°F)	58 mm (2.3 inches)	84%	moderate
April Weather	7°C (45°F)	87 mm (3.4 inches)	83%	very high
May Weather	15°C (59°F)	136 mm (5.4 inches)	75%	very high
June Weather	21°C (71°F)	122 mm (4.8 inches)	79%	very high
July Weather	23°C (74°F)	106 mm (4.2 inches)	75%	very high
August Weather	21°C (71°F)	111 mm (4.4 inches)	69%	very high
September Weather	18°C (65°F)	108 mm (4.2 inches)	74%	very high
October Weather	10°C (50°F)	120 mm (4.7 inches)	79%	moderate
November Weather	2°C (35°F)	51 mm (2.0 inches)	88%	moderate
December Weather	-3°C (27°F)	43 mm (1.7 inches)	82%	low