September Weather in Ankeny, United States

Last updated: June 24, 2025

In September, the average temperature in Ankeny, United States is a pleasant 20°C (68°F). However, be prepared for a range, as temperatures can dip to a minimum of 4°C (40°F) or soar up to a maximum of 34°C (93°F). With an average humidity of 73% and precipitation totaling 122 mm (4.8 in) over 10 days, it's wise to pack accordingly for this diverse weather!

September Temperature in Ankeny

In September in Ankeny, the average temperature is 20°C (68°F), with maximums reaching up to 34°C (93°F) and minimums dropping as low as 4°C (40°F). This variety in temperature makes it a great time for travelers to enjoy both outdoor activities and cozy indoor experiences.

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

The chart illustrates September temperature patterns in Ankeny, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ankeny, 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 4°C (40°F).

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

September Precipitation in Ankeny

In Ankeny in September, the total precipitation amount reaches 122 mm (4.8 in) over the course of 10 days.

September Precipitation Trends in Ankeny

The chart displays monthly precipitation patterns in Ankeny, 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 Ankeny, September typically receives around 122 mm (4.8 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 Ankeny

In Ankeny in September, humidity is 73%. With an average temperature of 20°C (68°F), this humidity feels like a warm embrace, making outdoor activities somewhat sticky, yet the atmosphere remains pleasant for leisurely strolls and sightseeing.

September Average Humidity in Ankeny

This chart illustrates the average monthly humidity levels in Ankeny, 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 Ankeny is approximately 73%, 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 Ankeny

In Ankeny 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 Ankeny.

Maximum UV Index Levels in Ankeny for September

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

Data source: Ankeny 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 Ankeny Compares to Other Months

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

This table compares monthly weather conditions in Ankeny, 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)	38 mm (1.5 inches)	78%	moderate
February Weather	-5°C (23°F)	42 mm (1.6 inches)	80%	moderate
March Weather	4°C (39°F)	81 mm (3.2 inches)	77%	high
April Weather	9°C (49°F)	77 mm (3.0 inches)	77%	very high
May Weather	17°C (62°F)	168 mm (6.6 inches)	77%	very high
June Weather	23°C (74°F)	112 mm (4.4 inches)	81%	extreme
July Weather	25°C (77°F)	74 mm (2.9 inches)	81%	very high
August Weather	23°C (74°F)	83 mm (3.3 inches)	77%	very high
September Weather	20°C (68°F)	122 mm (4.8 inches)	73%	very high
October Weather	11°C (53°F)	133 mm (5.2 inches)	75%	high
November Weather	3°C (38°F)	41 mm (1.6 inches)	85%	moderate
December Weather	-1°C (31°F)	37 mm (1.4 inches)	83%	moderate