Iowa City (IA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Iowa City, Iowa, United States of America. The numbers reflect climate data gathered over a 30-year period, from 1990 to 2020. Now, let's break down all the details for a clearer picture.

Iowa City has a relatively rain/snowy climate with high precipitation levels, averaging 1005 mm (40 in) of rain/snowfall annually. Despite the high annual total, it does experience a distinct dry season during certain months. Examine our detailed charts below to understand these seasonal patterns.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

The seasons in Iowa City, bring significant changes in precipitation. The wettest month, June, receives heavy rainfall, with an average of 160 mm (6.3 in) of precipitation. This rainfall is distributed across 13 rainy days.

In contrast, the driest month, January, experiences much less snowfall, totaling 24 mm (0.9 in) over 7 snowy days. These distinct seasonal differences provide diverse experiences throughout the year.

June, the wettest month, has a maximum daytime temperature of 28°C (82°F). During the driest month January you can expect a temperature of -1°C (30°F). For more detailed insights into the city's temperatures, visit our Iowa City Temperature page.

Annual Rainfall in the United States of America: City Comparison

The map below shows the annual precipitation across the United States of America. You can also select the different months in case you are interested in a specific month.

Iowa City vs World: Rainfall Compared

Iowa City's average annual precipitation is 1005 mm (40 in). Let's compare this to some popular worldwide tourist destinations:

In Lisbon, Portugal, the average annual precipitation is 774 mm (30 in), characterized by wet winters and dry summers typical of the Mediterranean climate.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.

Adelaide, Australia, enjoys 511 mm (20 in) of annual precipitation, with dry summers and wet winters.

Mumbai, India, experiences a tropical monsoon climate with 1860 mm (73 in) of annual rainfall, with the majority of precipitation happening during the monsoon season from June to September.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

Rainy Seasons: Many parts of the world have well-defined wet seasons where precipitation is distinctly higher. These are normally accompanied by lush vegetation and temperature patterns.

Dry Seasons: In areas where the climate is either desert or Mediterranean, the amount of precipitation is drastically reduced, leading to a shortage of water and arid conditions.

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
• Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.

For more detailed information about Iowa City (IA)'s weather, including sunshine hours, humidity levels, and temperature data, visit our Iowa City (IA) Climate page.