September Weather in Granite Falls, United States

Last updated: June 24, 2025

In Granite Falls, United States, the average temperature in September reaches a comfortable 18°C (65°F). However, be prepared for a range of temperatures—from a chilly 1°C (34°F) to a warm 33°C (92°F). Expect about 107 mm (4.2 in) of precipitation over 9 days, with an average humidity level of 82%. This combination makes for an intriguing climate—perfect for exploration!

September Temperature in Granite Falls

In September in Granite Falls, the average temperature is 18°C (65°F), with maximums reaching 33°C (92°F) and minimums dropping as low as 1°C (34°F). It's a great time to visit Granite Falls, offering a pleasant climate for outdoor activities and exploration.

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

The chart illustrates September temperature patterns in Granite Falls, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Granite Falls, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (92°F) and lows dropping to around 1°C (34°F).

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

September Precipitation in Granite Falls

In Granite Falls in September, the precipitation amount is 107 mm (4.2 in), occurring over a span of 9 days.

September Precipitation Trends in Granite Falls

The chart displays monthly precipitation patterns in Granite Falls, 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 Falls, September typically receives around 107 mm (4.2 inches) of precipitation spread over approximately 9 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 Falls

In Granite Falls in September, humidity is 82%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace that can quickly leave travelers feeling fatigued and in need of frequent breaks to stay refreshed and hydrated.

September Average Humidity in Granite Falls

This chart illustrates the average monthly humidity levels in Granite Falls, 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 Falls is approximately 82%, 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 Falls

In Granite Falls in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Granite Falls.

Maximum UV Index Levels in Granite Falls for September

The chart shows the monthly maximum UV Index (UVI) for Granite Falls 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 Falls typically reaches 7, which falls under the high exposure category.

Data source: Granite Falls 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 Falls Compares to Other Months

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

This table compares monthly weather conditions in Granite Falls, 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 (16°F)	21 mm (0.8 inches)	85%	moderate
February Weather	-9°C (16°F)	23 mm (0.9 inches)	89%	moderate
March Weather	0°C (33°F)	57 mm (2.3 inches)	81%	moderate
April Weather	6°C (43°F)	76 mm (3.0 inches)	82%	high
May Weather	15°C (59°F)	110 mm (4.3 inches)	76%	very high
June Weather	22°C (72°F)	86 mm (3.4 inches)	81%	very high
July Weather	23°C (74°F)	108 mm (4.3 inches)	82%	very high
August Weather	21°C (71°F)	125 mm (4.9 inches)	83%	very high
September Weather	18°C (65°F)	107 mm (4.2 inches)	82%	high
October Weather	9°C (48°F)	93 mm (3.7 inches)	82%	moderate
November Weather	1°C (34°F)	27 mm (1.1 inches)	87%	moderate
December Weather	-5°C (24°F)	39 mm (1.6 inches)	84%	low