September Weather in Saint Paul, United States

Last updated: June 24, 2025

In September, the average temperature in Saint Paul, United States is a pleasant 20°C (68°F), but be prepared for a range from a chilly 4°C (39°F) to a toasty 35°C (96°F). With 57 mm (2.2 in) of precipitation spread over 6 days, it’s wise to carry an umbrella. The air is fairly humid, with an average humidity level of 77%, making for a uniquely comfortable atmosphere.

September Temperature in Saint Paul

In September in Saint Paul, the average temperature is 20°C (68°F). Maximum can reach 35°C (96°F) and minimum can be as low as 4°C (39°F). This diverse temperature range makes it an ideal time for travelers to enjoy both warm and cooler activities in Saint Paul.

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

The chart illustrates September temperature patterns in Saint Paul, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint Paul, September typically has an average temperature of 20°C (68°F), with highs reaching up to 35°C (96°F) and lows dropping to around 4°C (39°F).

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

September Precipitation in Saint Paul

In Saint Paul in September, the precipitation amount is 57 mm (2.2 in) over a span of 6 days.

September Precipitation Trends in Saint Paul

The chart displays monthly precipitation patterns in Saint Paul, 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 Paul, September typically receives around 57 mm (2.2 inches) of precipitation spread over approximately 6 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 Saint Paul

In Saint Paul in September, humidity is 77%. With an average temperature of 20°C (68°F), this humidity feels like a warm, sticky embrace, making it essential for travelers to stay hydrated and take breaks in shaded areas to avoid feeling sluggish in the heat.

September Average Humidity in Saint Paul

This chart illustrates the average monthly humidity levels in Saint Paul, 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 Paul is approximately 77%, 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 Paul

In Saint Paul 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 Paul.

Maximum UV Index Levels in Saint Paul for September

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

Data source: Saint Paul 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 Paul Compares to Other Months

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

This table compares monthly weather conditions in Saint Paul, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (26°F)	25 mm (1.0 inches)	73%	moderate
February Weather	-4°C (25°F)	18 mm (0.7 inches)	81%	moderate
March Weather	4°C (40°F)	86 mm (3.4 inches)	69%	high
April Weather	9°C (49°F)	56 mm (2.2 inches)	71%	very high
May Weather	16°C (61°F)	144 mm (5.7 inches)	80%	very high
June Weather	23°C (74°F)	85 mm (3.3 inches)	83%	extreme
July Weather	25°C (77°F)	66 mm (2.6 inches)	84%	very high
August Weather	23°C (74°F)	84 mm (3.3 inches)	84%	very high
September Weather	20°C (68°F)	57 mm (2.2 inches)	77%	very high
October Weather	10°C (51°F)	88 mm (3.5 inches)	72%	high
November Weather	4°C (40°F)	21 mm (0.8 inches)	80%	moderate
December Weather	-1°C (30°F)	41 mm (1.6 inches)	79%	moderate