September Weather in Granite Bay, United States

Last updated: June 24, 2025

In September, the average temperature in Granite Bay, United States hovers at a warm 23°C (74°F). While minimum temperatures can dip to a chilly 9°C (49°F), the mercury can soar as high as a sweltering 43°C (110°F). Expect a modest precipitation amount of 6 mm (0.2 in) over just one day, and enjoy the typically pleasant atmosphere with an average humidity level of about 44%.

September Temperature in Granite Bay

In September in Granite Bay, the average temperature is 23°C (74°F). Maximum temperatures can reach up to 43°C (110°F), while minimums can drop to as low as 9°C (49°F). Travelers should be prepared for a wide range of temperatures during their visit.

September Weather in Granite Bay: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Granite Bay, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Granite Bay, September typically has an average temperature of 23°C (74°F), with highs reaching up to 43°C (110°F) and lows dropping to around 9°C (49°F).

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

September Precipitation in Granite Bay

In Granite Bay in September, the precipitation amount is 6 mm (0.2 in) over the course of 1 day.

September Precipitation Trends in Granite Bay

The chart displays monthly precipitation patterns in Granite Bay, 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 Granite Bay, September typically receives around 6 mm (0.2 inches) of precipitation spread over approximately 1 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 Granite Bay

In Granite Bay in September humidity is 44%. With an average temperature of 23°C (74°F), this humidity feels like a comfortable embrace, making it pleasant for traveling and exploring the sights without feeling overly hot or sticky.

September Average Humidity in Granite Bay

This chart illustrates the average monthly humidity levels in Granite Bay, 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 Granite Bay 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 Granite Bay

In Granite Bay 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 Granite Bay.

Maximum UV Index Levels in Granite Bay for September

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

Data source: Granite Bay 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 Granite Bay Compares to Other Months

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

This table compares monthly weather conditions in Granite Bay, 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)	144 mm (5.7 inches)	84%	moderate
February Weather	10°C (51°F)	139 mm (5.5 inches)	84%	moderate
March Weather	13°C (55°F)	139 mm (5.5 inches)	83%	high
April Weather	16°C (61°F)	64 mm (2.5 inches)	81%	very high
May Weather	20°C (68°F)	31 mm (1.2 inches)	74%	very high
June Weather	24°C (76°F)	5 mm (0.2 inches)	64%	extreme
July Weather	26°C (79°F)	0 mm (0.0 inches)	44%	extreme
August Weather	26°C (78°F)	0 mm (0.0 inches)	36%	very high
September Weather	23°C (74°F)	6 mm (0.2 inches)	44%	very high
October Weather	18°C (65°F)	46 mm (1.8 inches)	65%	high
November Weather	12°C (54°F)	79 mm (3.1 inches)	84%	moderate
December Weather	9°C (48°F)	129 mm (5.1 inches)	83%	moderate