Monthly Weather Report

Iowa Monthly Weather Summary – July 2026

General Summary

Temperatures averaged 76.1 degrees or 2.7 degrees above normal while precipitation totaled 4.26 inches or 0.09 inch above normal. July 2026 ties 1939 and 1988 as the 34th warmest and ranks as the 52nd wettest July in 154 years of statewide records. A warmer July occurred in 2012, while 2025 was wetter and the 2nd wettest on record.

Temperatures

Statewide average temperatures in July were up to five degrees warmer than normal. Little Sioux (Harrison County) reported the month’s high temperature of 102 degrees on the 27th, 17 degrees above normal. Spencer Municipal Airport (Clay County) reported the month’s low temperature of 45 degrees on the 23rd, 18 degrees below normal.

July 2026 temperatures in Iowa fluctuated considerably, beginning with generally seasonal conditions before warming through the middle of the month. Early July featured highs mostly in the 80s, with several periods reaching the mid to upper 80s. A more pronounced warming trend developed around mid-month, with temperatures rising into the upper 80s and low 90s, followed by a period of well-above normal heat from July 17-20. A sharp cool down followed the July 20 cold front. July 22-24 was notably cool, with highs mainly in the low to upper 70s, and the statewide average low on July 23 was 55 degrees, or eight degrees below normal. Temperatures then rebounded quickly, with low 90s returning on July 25th and an intense heat episode on July 26th. Highs reached the mid to upper 90s, while very high dew points produced exceptionally high heat indices, including 121 degrees at Burlington and 124 degrees at Ames (Story County).  The heat eased after July 27th, although afternoon temperatures remained in the 80s to low 90s through July 29th. The month ended with more seasonal temperatures, generally ranging from the upper 70s north to low 80s south on July 30th.

Cooling Degree Days

Home cooling requirements, as estimated by cooling degree day totals, were 9% more than last July and 28% more than normal. Cooling degree day totals since January are 1% less than last year at this time and 17% more than normal.

Precipitation

Many of the state’s National Weather Service co-op and Community Collaborative Rain, Hail and Snow (CoCoRaHS) stations reported below-average rainfall with general departures in the one-to-three-inch range. However, stations in central to northeast Iowa registered 200-300 percent of normal through July, with totals approaching six inches over the 30-year climatology. Monthly precipitation totals ranged from 0.21 inch in Farmington (Van Buren County) to 15.64 inches in Ankeny (Polk County).

July precipitation was highly variable across Iowa, with several periods of heavy thunderstorm activity producing localized excessive rainfall and flooding. The month began with a particularly wet stretch, as widespread thunderstorms on July 2nd produced a statewide average of 1.30 inches, with localized totals of 6.50 inches near Nevada and up to 9.41 inches near Polk City (Polk County). Additional heavy rainfall on July 3-4 resulted in a statewide average of 0.83 inch, with 4.20-6.36 inches recorded at several stations in Ames. (Story County). Periodic thunderstorms continued through mid-July, generally producing lighter and more localized rainfall, although parts of central, northeastern, and southeastern Iowa received several inches during individual events. Another significant rainfall event occurred on July 20th, when severe thunderstorms produced torrential rain and flash flooding across portions of eastern Iowa; more than half of reporting stations recorded at least 1.00 inch, nearly 75 stations received 2.00 inches or more, and the statewide average was 1.14 inches. Much of northwest Iowa remained comparatively dry during this event. The month concluded with another widespread rainfall event on July 30-31st, particularly across eastern and northeastern Iowa, where more than 75 stations recorded at least 1.00 inch and localized totals reached 4.15 inches near Anamosa (Jones County). Overall, July precipitation was characterized by episodic, high-intensity thunderstorms, substantial spatial variability, and several localized areas receiving excessive rainfall and experiencing flooding.

Severe Weather

July 2026 was an active month for severe weather across Iowa, with multiple episodes of damaging winds, large hail, tornadoes and locally excessive rainfall. A prolonged period of thunderstorms on July 2nd produced widespread heavy rainfall, with nearly 200 stations receiving at least 2.00 inches and localized totals approaching 9.00 inches. Additional severe storms on July 8-10 produced several 60-mph wind gusts and a brief tornado near Swaledale (Cerro Gordo County). The most notable severe weather episode of the month occurred July 20, when a morning mesoscale convective system (MCS) produced a 70-mph wind gust and flash flooding in eastern Iowa, followed by afternoon supercells that generated 2.00-3.00-inch hail, two tornadoes in Hamilton County and widespread 40-60-mph winds. Heavy rainfall accompanied the storms, with more than half of reporting stations receiving at least 1.00 inch and localized totals exceeding 4.00 inches.

US Drought Monitor (USDM)

As of July 7th, 10% of Iowa was classified in Moderate Drought (D1) with 21% of the state in Abnormal Dryness (D0). Drier conditions along with warmer temperatures allowed D1 to expand across western Iowa through the month. Abnormal dryness also expanded and was introduced in southeast Iowa. As of the first map of August, 18% of the state was in D0 with 26% in D1. According to the Iowa Drought Plan (IDP) trigger tables updated on August 6th, Drought Regions 1 and 4 are classified as in “Watch.”

Justin Glisan, Ph.D.
State Climatologist of Iowa
Iowa Dept. of Agriculture & Land Stewardship
Hoover State Office Bldg.
Des Moines, IA 50319
Telephone: (515) 281-8981
E-mail: [email protected]

Weather by Districts

* Departures are computed from 1991-2020 normals.                                        
The weather data in this report are based upon information collected by the U. S. Dept. of Commerce, NOAA National Weather Service.