Excessive Heat in Iowa

Events

515

Deaths

0

Injuries

28

Damage

$7.2 million

• Excessive Heat in Iowa, July 15 to 28, 2011$6.9 million · 51 eventsA large area of high pressure developed in the upper atmosphere by the middle of July. Heat built up over Iowa, aided by the severe drought to the south across Kansas, Oklahoma, and Texas. Temperatures rose into the 90s each day through the period.
• Excessive Heat in Iowa, July 4 to 7, 201214 injured · 21 eventsA very hot and humid airmass surged into the Midwest during the long 4th of July holiday. The dangerous heat began about noon on July 4 with relief from the heat and humidity finally arriving during the evening of July 7.
• Excessive Heat in Iowa, July 17 to 20, 20114 injured · $272,000 · 8 eventsWarm and humid air invaded northeast Iowa on July 17th and remained in place for the next three days. During this stretch, afternoon heat indices routinely topped out between 110 and 120. Little relief occurred at night, as overnight lows remained in the 70s.
• Excessive Heat in Iowa, July 2 to 6, 201210 injured · 11 eventsA combination of high heat and humidity persisted for several days. Daytime temperatures reached the 90s to several degrees above 100, and dew points were in the 70s. The heat index went as high as 110 degrees.
• Excessive Heat in Iowa, July 17 to 20, 201951 eventsA large area of high pressure strengthened across the area through the week resulting in hot temperatures and high humidity values in place across Iowa for a prolonged period of time.
• Excessive Heat in Iowa, July 20 to 23, 201647 eventsA warm front lifted through the state on the 20th, allowing southerly winds to bring about high temperatures in the low 90s along with dew points in the upper 70s to 80 at times. As a result, heat index values easily eclipsed the 100-105 degree range and at times exceeded 110.
• Excessive Heat and Damaging Winds in Iowa, July 29 to 31, 202478 kt wind · 16 eventsThe prevailing upper-level pattern for the end of July featured a trough over the Pacific Northwest, favoring southwesterly flow over the central Great Plains. Two troughs ejected out into the north-central CONUS during this episode.
• Excessive Heat in Iowa, July 15 to 20, 201111 eventsSeveral consecutive days were experienced with an extremely stressful combination of high heat and humidity. Heat indices frequently rose above 115 degrees during the day, with temperatures reaching the 90s and dew points remaining in the 70s to lower 80s.
• Excessive Heat in Iowa, June 27, 201211 eventsA combination of high heat and humidity, with temperatures reaching the 90s and dew points in the 70s, pushed the heat index to a little above 100 degrees over northwest Iowa during the afternoon and early evening hours.
• Excessive Heat in Iowa, July 18 to 24, 201211 eventsA combination of high heat and humidity persisted for several days. Daytime temperatures reached the 90s to a few degrees above 100, and dew points were in the 70s. The heat index went as high as 110 degrees.
• Excessive Heat in Iowa, July 15 to 16, 201211 eventsA combination of high heat and humidity consisted of daytime temperatures reaching the 90s and dew points in the 70s. The heat index went as high as 105 degrees.
• Excessive Heat in Iowa, June 10 to 12, 201611 eventsRapidly developing very hot and humid weather, with daytime temperatures reaching the mid to upper 90s, brought the heat index to 100 or a little hotter during the afternoon hours of June 10th through June 12th.
• Excessive Heat in Iowa, July 20 to 23, 201611 eventsVery hot and very humid weather, with daytime temperatures reaching the 95 to 100 degree range, brought the heat index to 100 to 115 degrees during the afternoon hours of July 20th through July 23rd.
• Excessive Heat and Heat in Iowa, June 29, 201911 eventsOppressive temperatures in the mid 90's to around 100 degrees along with dew point readings in the mid to upper 70's produced very dangerous heat conditions with heat index readings in excess of 105 degrees for much of the afternoon and early evening.
• Excessive Heat in Iowa, July 25 to 28, 202311 eventsStrong high pressure and elevated near surface moisture resulted in a multi-day heat wave across southeast South Dakota, southwest Minnesota, northwest Iowa, and northeast Nebraska from July 25-28.
• Excessive Heat in Iowa, August 21 to 24, 202311 eventsAn immense ridge of high pressure over the Central Plains and Mississippi Valley entrenched heat and high dewpoint air across the region, resulting in daily heat indices from 100 to around 120, with very little recovery during the overnight hours.
• Excessive Heat in Iowa, August 19, 202311 eventsAn expanding upper-level ridge across the southern and central U.S. pushed heat into the region, as moisture pooled just ahead of an advancing frontal zone. The combination of heat and higher dewpoints resulted in afternoon and early evening heat indices from 100 to 115 degrees.
• Excessive Heat in Iowa, July 13 to 15, 202411 eventsVery warm temperatures with highs in the lower to mid 90s paired with oppressive dew point readings in the upper 70s to lower 80s produced afternoon and evening heat indices generally from 100 to 120 degrees with little overnight recovery.
• Excessive Heat and Heat in Iowa, July 31, 202411 eventsPooling moisture ahead of a frontal boundary pushed dew point readings into the upper 70s and lower 80s, and temperatures in the upper 80s to lower 90s produced heat index values from 100 to 113 degrees.
• Excessive Heat in Iowa, August 25 to 26, 202411 eventsA strong ridge of high pressure locked in very warm and extremely humid conditions. Dew points in the upper 70s and lower 80s combined with temperatures in the upper 80s to lower 90s to produce daily heat index values from 100 to 120 degrees.
• Excessive Heat and Heat in Iowa, August 5, 202411 eventsAreas ahead of a weak frontal boundary exhibited pooling of moisture with dew point readings into the upper 70s to lower 80s.
• Excessive Heat in Iowa, June 20 to 22, 202511 eventsThe upper-level pattern experienced amplification of an eastern U.S. ridge and western U.S. trough, which locked a low-level frontal boundary in place from western Nebraska through central South Dakota into the Great Lakes.
• Excessive Heat and Heat in Iowa, August 15 to 17, 202511 eventsHeat and moisture pooled near and south of a nearly stationary frontal boundary across eastern South Dakota and southern Minnesota.
• Excessive Heat in Iowa, July 27 to 28, 202511 eventsBeneath an expansive and strong, flat ridge aloft, extreme surface-based moisture returned near a diffuse warm frontal boundary on July 26 and lasted into the afternoon of July 28.
• Excessive Heat and Heat in Iowa, July 21 to 23, 202511 eventsMoisture pooled in the vicinity of a nearly stationary boundary early on July 21, which slowly worked northward as a warm front over the next two days while a large upper level ridge expanded across the Northern Plains.

Excessive Heat everywhereEvery kind of event in Iowa

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.