September Weather in Merrill, United States

Last updated: June 24, 2025

In Merrill, United States, the average temperature in September is a pleasant 19°C (67°F). However, be prepared for temperature fluctuations, with a minimum of 3°C (38°F) and a maximum reaching up to 34°C (93°F). Expect some rain, as precipitation averages 105 mm (4.1 in) over about 8 days during the month, and keep in mind that the average humidity is quite high at 75%. Stay comfortable and enjoy your time!

September Temperature in Merrill

In September in Merrill, the average temperature is 19°C (67°F), with maximums reaching 34°C (93°F) and minimums dropping as low as 3°C (38°F). This climate makes it an ideal destination for travelers seeking a mix of warm days and cooler evenings.

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

The chart illustrates September temperature patterns in Merrill, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Merrill, September typically has an average temperature of 19°C (67°F), with highs reaching up to 34°C (93°F) and lows dropping to around 3°C (38°F).

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

September Precipitation in Merrill

In Merrill in September, the precipitation amount is 105 mm (4.1 in) over the course of 8 days.

September Precipitation Trends in Merrill

The chart displays monthly precipitation patterns in Merrill, 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 Merrill, September typically receives around 105 mm (4.1 inches) of precipitation spread over approximately 8 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Merrill

In Merrill in September humidity is 75%. With an average temperature of 19°C (67°F), this humidity feels like a warm embrace, making travel invigorating yet slightly sticky, as you navigate through the vibrant streets or scenic landscapes.

September Average Humidity in Merrill

This chart illustrates the average monthly humidity levels in Merrill, 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 Merrill is approximately 75%, 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 Merrill

In Merrill 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 Merrill.

Maximum UV Index Levels in Merrill for September

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

Data source: Merrill 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 Merrill Compares to Other Months

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

This table compares monthly weather conditions in Merrill, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-6°C (22°F)	27 mm (1.1 inches)	80%	low
February Weather	-6°C (22°F)	30 mm (1.2 inches)	84%	moderate
March Weather	3°C (37°F)	76 mm (3.0 inches)	75%	moderate
April Weather	8°C (47°F)	87 mm (3.4 inches)	79%	very high
May Weather	16°C (60°F)	142 mm (5.6 inches)	74%	very high
June Weather	23°C (74°F)	105 mm (4.1 inches)	81%	extreme
July Weather	24°C (76°F)	70 mm (2.7 inches)	82%	very high
August Weather	22°C (73°F)	105 mm (4.1 inches)	80%	very high
September Weather	19°C (67°F)	105 mm (4.1 inches)	75%	very high
October Weather	10°C (50°F)	78 mm (3.1 inches)	77%	moderate
November Weather	2°C (37°F)	27 mm (1.1 inches)	85%	moderate
December Weather	-2°C (28°F)	40 mm (1.6 inches)	83%	moderate