September Weather in Foresthill, United States

Last updated: June 24, 2025

In Foresthill, United States, the average temperature in September hovers around 20°C (68°F), creating a pleasant atmosphere for outdoor activities. However, temperatures can range from a brisk 4°C (39°F) to a sizzling 39°C (103°F), so be prepared for the extremes! Expect 20 mm (0.8 in) of precipitation over the course of 3 days, with an average humidity of 44%, making this month a balanced blend of comfort and refreshment.

September Temperature in Foresthill

In September in Foresthill, the average temperature is 20°C (68°F), with maximums reaching 39°C (103°F) and minimums dropping as low as 4°C (39°F). This diverse temperature range makes Foresthill a destination where travelers should be prepared for both warm days and cooler evenings.

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

The chart illustrates September temperature patterns in Foresthill, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Foresthill, September typically has an average temperature of 20°C (68°F), with highs reaching up to 39°C (103°F) and lows dropping to around 4°C (39°F).

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

September Precipitation in Foresthill

In Foresthill in September, the precipitation amount is 20 mm (0.8 in) accumulated over a period of 3 days.

September Precipitation Trends in Foresthill

The chart displays monthly precipitation patterns in Foresthill, 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 Foresthill, September typically receives around 20 mm (0.8 inches) of precipitation spread over approximately 3 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 Foresthill

In Foresthill in September, humidity is 44%. With an average temperature of 20°C (68°F), this humidity feels like a comfortable embrace, making it ideal for exploring the sights without feeling overly sticky or drained.

September Average Humidity in Foresthill

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

In Foresthill 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 Foresthill.

Maximum UV Index Levels in Foresthill for September

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

Data source: Foresthill 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 Foresthill Compares to Other Months

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

This table compares monthly weather conditions in Foresthill, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	6°C (42°F)	253 mm (9.9 inches)	84%	moderate
February Weather	6°C (43°F)	254 mm (10.0 inches)	84%	moderate
March Weather	7°C (45°F)	262 mm (10.3 inches)	83%	very high
April Weather	11°C (52°F)	126 mm (5.0 inches)	81%	very high
May Weather	15°C (59°F)	78 mm (3.1 inches)	74%	extreme
June Weather	20°C (69°F)	14 mm (0.6 inches)	64%	extreme
July Weather	24°C (76°F)	2 mm (0.1 inches)	44%	extreme
August Weather	24°C (75°F)	4 mm (0.1 inches)	36%	very high
September Weather	20°C (68°F)	20 mm (0.8 inches)	44%	very high
October Weather	14°C (58°F)	69 mm (2.7 inches)	65%	high
November Weather	9°C (49°F)	143 mm (5.6 inches)	84%	moderate
December Weather	5°C (42°F)	194 mm (7.6 inches)	83%	moderate