May Weather in Iowa, United States

Last updated: June 24, 2025

In May, the average temperature in Iowa, United States hovers around 25°C (77°F), offering a warm climate for visitors. Expect temperatures to range from a chilly 10°C (51°F) to a sweltering 36°C (97°F). During this month, precipitation totals 193 mm (7.6 in) over roughly 12 days, contributing to an average humidity of 81%. Whether you're exploring or relaxing, be prepared for a mix of warmth and occasional rain!

May Temperature in Iowa

In May in Iowa, the average temperature is 25°C (77°F). The maximum can reach 36°C (97°F), and the minimum can be as low as 10°C (51°F). This makes Iowa an ideal destination for travelers seeking warm weather with some cool evenings.

May Weather in Iowa: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Iowa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iowa, May typically has an average temperature of 25°C (77°F), with highs reaching up to 36°C (97°F) and lows dropping to around 10°C (51°F).

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

May Precipitation in Iowa

In Iowa in May, the precipitation amount is 193 mm (7.6 in) spread over 12 days.

May Precipitation Trends in Iowa

The chart displays monthly precipitation patterns in Iowa, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Iowa, May typically receives around 193 mm (7.6 inches) of precipitation spread over approximately 12 days.

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

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Millimeters (mm) Inches (in)

May Humidity in Iowa

In Iowa in May, humidity is 81%. With an average temperature of 25°C (77°F), this humidity feels like walking through a warm, thick blanket, making traveling quite challenging as you may feel sticky and sluggish, requiring frequent breaks to stay refreshed and hydrated.

May Average Humidity in Iowa

This chart illustrates the average monthly humidity levels in Iowa, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Iowa is approximately 81%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Iowa

In Iowa in May, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Iowa.

Maximum UV Index Levels in Iowa for May

The chart shows the monthly maximum UV Index (UVI) for Iowa in May, 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 May, the maximum UV index in Iowa typically reaches 11, which falls under the extreme exposure category.

Data source: Iowa May 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 May Weather in Iowa Compares to Other Months

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

This table compares monthly weather conditions in Iowa, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	12°C (53°F)	117 mm (4.6 inches)	81%	moderate
February Weather	14°C (58°F)	107 mm (4.2 inches)	81%	very high
March Weather	18°C (65°F)	70 mm (2.7 inches)	79%	very high
April Weather	20°C (69°F)	155 mm (6.1 inches)	80%	very high
May Weather	25°C (77°F)	193 mm (7.6 inches)	81%	extreme
June Weather	27°C (81°F)	163 mm (6.4 inches)	76%	extreme
July Weather	28°C (83°F)	158 mm (6.2 inches)	73%	extreme
August Weather	28°C (83°F)	179 mm (7.1 inches)	71%	extreme
September Weather	26°C (80°F)	163 mm (6.4 inches)	72%	very high
October Weather	22°C (72°F)	122 mm (4.8 inches)	73%	very high
November Weather	16°C (60°F)	75 mm (2.9 inches)	83%	high
December Weather	14°C (57°F)	119 mm (4.7 inches)	88%	moderate