September Weather in Penn Valley, United States

Last updated: June 24, 2025

In Penn Valley, United States, the average temperature in September is a pleasant 23°C (73°F), perfect for enjoying outdoor activities. Temperatures can vary significantly, with a minimum of 6°C (44°F) and soaring up to a sizzling 42°C (107°F). Expect 12 mm (0.5 in) of precipitation over 2 days, adding a touch of freshness to the warm climate. With an average humidity of 44%, you can comfortably explore all that this vibrant destination has to offer!

September Temperature in Penn Valley

In September in Penn Valley, the average temperature is 23°C (73°F). The maximum can reach 42°C (107°F), and the minimum can be as low as 6°C (44°F). Travelers should be prepared for a wide range of temperatures and plan their activities accordingly.

September Weather in Penn Valley: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Penn Valley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Penn Valley, September typically has an average temperature of 23°C (73°F), with highs reaching up to 42°C (107°F) and lows dropping to around 6°C (44°F).

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

September Precipitation in Penn Valley

In Penn Valley in September, the precipitation amount is 12 mm (0.5 in) over the course of 2 days.

September Precipitation Trends in Penn Valley

The chart displays monthly precipitation patterns in Penn Valley, 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 Penn Valley, September typically receives around 12 mm (0.5 inches) of precipitation spread over approximately 2 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 Penn Valley

In Penn Valley in September humidity is 44%. With an average temperature of 23°C (73°F), this humidity feels like a pleasant embrace, making it comfortable for travelers to explore and enjoy outdoor activities without feeling too sticky or overheated.

September Average Humidity in Penn Valley

This chart illustrates the average monthly humidity levels in Penn Valley, 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 Penn Valley is approximately 44%, 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 Penn Valley

In Penn Valley 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 Penn Valley.

Maximum UV Index Levels in Penn Valley for September

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

Data source: Penn Valley 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 Penn Valley Compares to Other Months

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

This table compares monthly weather conditions in Penn Valley, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (48°F)	196 mm (7.7 inches)	84%	moderate
February Weather	9°C (49°F)	202 mm (8.0 inches)	84%	moderate
March Weather	11°C (52°F)	191 mm (7.5 inches)	83%	high
April Weather	15°C (59°F)	89 mm (3.5 inches)	81%	very high
May Weather	19°C (66°F)	48 mm (1.9 inches)	74%	very high
June Weather	24°C (76°F)	9 mm (0.3 inches)	64%	extreme
July Weather	27°C (81°F)	1 mm (0.0 inches)	44%	extreme
August Weather	26°C (79°F)	1 mm (0.0 inches)	36%	very high
September Weather	23°C (73°F)	12 mm (0.5 inches)	44%	very high
October Weather	17°C (63°F)	62 mm (2.4 inches)	65%	high
November Weather	12°C (53°F)	115 mm (4.5 inches)	84%	moderate
December Weather	8°C (47°F)	170 mm (6.7 inches)	83%	moderate