September Weather in Grantsville, United States

Last updated: June 24, 2025

In September, the average temperature in Grantsville, United States is a pleasant 20°C (68°F). However, prepare for a range, as temperatures can drop to a minimum of 3°C (37°F) and soar to a maximum of 37°C (98°F). Expect 31 mm (1.2 in) of precipitation over about 3 days, coupled with an average humidity of 42%.

September Temperature in Grantsville

In September in Grantsville, the average temperature is 20°C (68°F), with maximums reaching up to 37°C (98°F) and minimums dropping as low as 3°C (37°F). This varied climate makes Grantsville an ideal destination for travelers seeking a mix of warmth and coolness.

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

The chart illustrates September temperature patterns in Grantsville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grantsville, September typically has an average temperature of 20°C (68°F), with highs reaching up to 37°C (98°F) and lows dropping to around 3°C (37°F).

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

September Precipitation in Grantsville

In Grantsville in September, the precipitation amount is 31 mm (1.2 in) over the course of 3 days.

September Precipitation Trends in Grantsville

The chart displays monthly precipitation patterns in Grantsville, 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 Grantsville, September typically receives around 31 mm (1.2 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 Grantsville

In Grantsville in September humidity is 42%. With an average temperature of 20°C (68°F), this humidity feels like a comfortable and refreshing breeze, making it ideal for traveling and exploring the local attractions without worrying about overheating.

September Average Humidity in Grantsville

This chart illustrates the average monthly humidity levels in Grantsville, 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 Grantsville is approximately 42%, 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 Grantsville

In Grantsville 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 Grantsville.

Maximum UV Index Levels in Grantsville for September

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

Data source: Grantsville 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 Grantsville Compares to Other Months

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

This table compares monthly weather conditions in Grantsville, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-1°C (31°F)	40 mm (1.6 inches)	85%	moderate
February Weather	1°C (34°F)	47 mm (1.8 inches)	86%	moderate
March Weather	6°C (43°F)	61 mm (2.4 inches)	79%	high
April Weather	10°C (50°F)	56 mm (2.2 inches)	71%	very high
May Weather	15°C (60°F)	49 mm (1.9 inches)	59%	extreme
June Weather	23°C (73°F)	14 mm (0.5 inches)	55%	extreme
July Weather	27°C (81°F)	16 mm (0.6 inches)	44%	extreme
August Weather	26°C (78°F)	18 mm (0.7 inches)	34%	extreme
September Weather	20°C (68°F)	31 mm (1.2 inches)	42%	very high
October Weather	10°C (51°F)	33 mm (1.3 inches)	63%	high
November Weather	5°C (41°F)	27 mm (1.1 inches)	81%	moderate
December Weather	-1°C (31°F)	36 mm (1.4 inches)	84%	moderate