September Weather in Grand Mound, United States

Last updated: June 24, 2025

In September, the average temperature in Grand Mound, United States hovers around 20°C (68°F). While temperatures can dip to a chilly 3°C (38°F), they can soar up to a scorching 34°C (93°F). This month also brings approximately 119 mm (4.7 in) of precipitation across 10 days, contributing to an average humidity of 78%. Stay prepared for a mix of warmth and wetness as you experience the unique climate of Grand Mound!

September Temperature in Grand Mound

In September in Grand Mound, the average temperature is 20°C (68°F). Maximums can reach 34°C (93°F), and minimums can be as low as 3°C (38°F). Be prepared for a range of weather conditions during your travels!

September Weather in Grand Mound: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Grand Mound, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grand Mound, September typically has an average temperature of 20°C (68°F), with highs reaching up to 34°C (93°F) and lows dropping to around 3°C (38°F).

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

September Precipitation in Grand Mound

In Grand Mound in September, the total precipitation amount is 119 mm (4.7 in) over the span of 10 days.

September Precipitation Trends in Grand Mound

The chart displays monthly precipitation patterns in Grand Mound, 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 Grand Mound, September typically receives around 119 mm (4.7 inches) of precipitation spread over approximately 10 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 Grand Mound

In Grand Mound in September humidity is 78%. With an average temperature of 20°C (68°F), this humidity feels like a warm, enveloping blanket that makes exploring the sights a bit sticky, so travelers should stay hydrated and take frequent breaks in the shade.

September Average Humidity in Grand Mound

This chart illustrates the average monthly humidity levels in Grand Mound, 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 Grand Mound is approximately 78%, 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 Grand Mound

In Grand Mound in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Grand Mound.

Maximum UV Index Levels in Grand Mound for September

The chart shows the monthly maximum UV Index (UVI) for Grand Mound 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 Grand Mound typically reaches 8, which falls under the very high exposure category.

Data source: Grand Mound 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 Grand Mound Compares to Other Months

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

This table compares monthly weather conditions in Grand Mound, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-5°C (23°F)	52 mm (2.1 inches)	81%	moderate
February Weather	-4°C (25°F)	59 mm (2.3 inches)	81%	moderate
March Weather	4°C (39°F)	82 mm (3.2 inches)	81%	high
April Weather	9°C (49°F)	96 mm (3.8 inches)	82%	very high
May Weather	17°C (62°F)	140 mm (5.5 inches)	78%	very high
June Weather	23°C (73°F)	121 mm (4.7 inches)	81%	extreme
July Weather	25°C (76°F)	76 mm (3.0 inches)	79%	very high
August Weather	23°C (73°F)	84 mm (3.3 inches)	77%	very high
September Weather	20°C (68°F)	119 mm (4.7 inches)	78%	very high
October Weather	12°C (54°F)	119 mm (4.7 inches)	78%	high
November Weather	3°C (39°F)	49 mm (1.9 inches)	87%	moderate
December Weather	0°C (32°F)	47 mm (1.9 inches)	84%	low