September Weather in Graton, United States

Last updated: June 24, 2025

The average temperature in Graton, United States during September is a pleasant 20°C (69°F). However, temperatures can fluctuate, with minimums dipping as low as 7°C (45°F) and maximums soaring up to 41°C (105°F). You can expect a light sprinkle, with precipitation averaging just 2 mm (0.1 in) over 0 days of the month. Humidity remains quite comfortable at around 68%.

September Temperature in Graton

In September in Graton, the average temperature is 20°C (69°F). Maximum temperatures can reach 41°C (105°F), while minimums can drop as low as 7°C (45°F). Be prepared for a wide range of temperatures when traveling during this month.

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

The chart illustrates September temperature patterns in Graton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Graton, September typically has an average temperature of 20°C (69°F), with highs reaching up to 41°C (105°F) and lows dropping to around 7°C (45°F).

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

September Precipitation in Graton

In Graton in September, the precipitation amount is 2 mm (0.1 in) during a span of 0 days.

September Precipitation Trends in Graton

The chart displays monthly precipitation patterns in Graton, 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 Graton, September typically receives around 2 mm (0.1 inches) of precipitation spread over approximately 0 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 Graton

In Graton in September, humidity is 68%. With an average temperature of 20°C (69°F), this humidity feels like a warm embrace, making outdoor exploration both refreshing and slightly sticky, requiring occasional breaks in the shade to stay comfortable while traveling.

September Average Humidity in Graton

This chart illustrates the average monthly humidity levels in Graton, 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 Graton is approximately 68%, 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 Graton

In Graton 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 Graton.

Maximum UV Index Levels in Graton for September

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

Data source: Graton 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 Graton Compares to Other Months

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

This table compares monthly weather conditions in Graton, 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 (49°F)	139 mm (5.5 inches)	86%	moderate
February Weather	10°C (50°F)	155 mm (6.1 inches)	84%	moderate
March Weather	11°C (52°F)	97 mm (3.8 inches)	83%	high
April Weather	14°C (57°F)	45 mm (1.8 inches)	80%	very high
May Weather	17°C (62°F)	27 mm (1.1 inches)	80%	very high
June Weather	21°C (69°F)	2 mm (0.1 inches)	76%	extreme
July Weather	22°C (71°F)	0 mm (0.0 inches)	70%	extreme
August Weather	21°C (71°F)	0 mm (0.0 inches)	66%	very high
September Weather	20°C (69°F)	2 mm (0.1 inches)	68%	very high
October Weather	17°C (63°F)	41 mm (1.6 inches)	72%	high
November Weather	12°C (54°F)	58 mm (2.3 inches)	84%	moderate
December Weather	9°C (48°F)	101 mm (4.0 inches)	84%	moderate