September Weather in Jefferson, United States

Last updated: June 24, 2025

In September, the average temperature in Jefferson, United States is a warm 27°C (80°F), perfect for enjoying the outdoors. Temperatures can range from a cool 17°C (63°F) to a sizzling 34°C (94°F). Be prepared for some moisture, as 148 mm (5.8 in) of precipitation typically falls over 15 days, contributing to an average humidity of 79%.

September Temperature in Jefferson

In September in Jefferson, the average temperature is 27°C (80°F). The maximum can reach 34°C (94°F), and the minimum can be as low as 17°C (63°F). This weather makes Jefferson an ideal destination for travelers seeking warm and pleasant conditions.

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

The chart illustrates September temperature patterns in Jefferson, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Jefferson, September typically has an average temperature of 27°C (80°F), with highs reaching up to 34°C (94°F) and lows dropping to around 17°C (63°F).

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

September Precipitation in Jefferson

In Jefferson, in September, the precipitation amount is 148 mm (5.8 in) over a span of 15 days.

September Precipitation Trends in Jefferson

The chart displays monthly precipitation patterns in Jefferson, 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 Jefferson, September typically receives around 148 mm (5.8 inches) of precipitation spread over approximately 15 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 Jefferson

In Jefferson in September humidity is 79%. With an average temperature of 27°C (80°F), this humidity feels like walking through a warm, dense blanket, making travel feel sluggish and allowing every step to become noticeably heavier.

September Average Humidity in Jefferson

This chart illustrates the average monthly humidity levels in Jefferson, 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 Jefferson 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 Jefferson

In Jefferson 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 Jefferson.

Maximum UV Index Levels in Jefferson for September

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

Data source: Jefferson 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 Jefferson Compares to Other Months

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

This table compares monthly weather conditions in Jefferson, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	13°C (55°F)	92 mm (3.6 inches)	81%	moderate
February Weather	15°C (60°F)	107 mm (4.2 inches)	81%	very high
March Weather	18°C (65°F)	85 mm (3.4 inches)	79%	very high
April Weather	21°C (70°F)	110 mm (4.3 inches)	81%	extreme
May Weather	25°C (77°F)	140 mm (5.5 inches)	77%	extreme
June Weather	27°C (81°F)	206 mm (8.1 inches)	74%	extreme
July Weather	28°C (83°F)	203 mm (8.0 inches)	74%	extreme
August Weather	28°C (83°F)	257 mm (10.1 inches)	73%	extreme
September Weather	27°C (80°F)	148 mm (5.8 inches)	79%	very high
October Weather	23°C (74°F)	128 mm (5.0 inches)	77%	very high
November Weather	17°C (62°F)	67 mm (2.6 inches)	81%	high
December Weather	14°C (58°F)	110 mm (4.3 inches)	84%	moderate