September Weather in Florence, United States

Last updated: June 24, 2025

The average temperature in Florence, United States during September is a comfortable 18°C (64°F), with a range that can drop to a chilly -2°C (28°F) or soar to a warm 34°C (94°F). Expect about 31 mm (1.2 in) of precipitation spread over 6 days, contributing to an average humidity of 65%. Enjoy the varied climate as you explore!

September Temperature in Florence

In September in Florence, the average temperature is 18°C (64°F), with maximums reaching 34°C (94°F) and minimums dropping to as low as -2°C (28°F). Travelers should be prepared for a wide range of temperatures, making it essential to pack accordingly.

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

The chart illustrates September temperature patterns in Florence, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Florence, September typically has an average temperature of 18°C (64°F), with highs reaching up to 34°C (94°F) and lows dropping to around -2°C (28°F).

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

September Precipitation in Florence

In Florence in September, the precipitation amount is 31 mm (1.2 in) over a span of 6 days.

September Precipitation Trends in Florence

The chart displays monthly precipitation patterns in Florence, 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 Florence, September typically receives around 31 mm (1.2 inches) of precipitation spread over approximately 6 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 Florence

In Florence in September, humidity is 65%. With an average temperature of 18°C (64°F), this humidity feels like a slightly muggy embrace, making outdoor exploration enjoyable but requiring a light jacket and frequent hydration breaks.

September Average Humidity in Florence

This chart illustrates the average monthly humidity levels in Florence, 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 Florence is approximately 65%, 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 Florence

In Florence in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Florence.

Maximum UV Index Levels in Florence for September

The chart shows the monthly maximum UV Index (UVI) for Florence 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 Florence typically reaches 10, which falls under the very high exposure category.

Data source: Florence 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 Florence Compares to Other Months

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

This table compares monthly weather conditions in Florence, 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 (28°F)	15 mm (0.6 inches)	88%	moderate
February Weather	-3°C (28°F)	21 mm (0.8 inches)	87%	high
March Weather	4°C (39°F)	37 mm (1.5 inches)	81%	very high
April Weather	8°C (46°F)	41 mm (1.6 inches)	76%	extreme
May Weather	13°C (55°F)	64 mm (2.5 inches)	66%	extreme
June Weather	20°C (68°F)	42 mm (1.7 inches)	58%	extreme
July Weather	22°C (72°F)	78 mm (3.1 inches)	52%	extreme
August Weather	21°C (70°F)	62 mm (2.4 inches)	56%	extreme
September Weather	18°C (64°F)	31 mm (1.2 inches)	65%	very high
October Weather	9°C (48°F)	25 mm (1.0 inches)	76%	high
November Weather	3°C (38°F)	15 mm (0.6 inches)	82%	moderate
December Weather	-1°C (31°F)	11 mm (0.4 inches)	89%	moderate