Iowa, 2026

Excessive Heat in Iowa, June 29 to 30, 2026

June 29 to 30, 2026 · NWS ARX · 8 events in 8 counties and zones

During the last two days of June, a favorable synoptic weather pattern brought extreme heat to portions of northeast Iowa as ample moisture resulted in remarkably high dewpoints. Consequently, heat indices soared well above 100 degrees with numerous locations seeing heat indices of 110 to 115 degrees or even higher in some locations.

Where it happened

Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
8

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS ARX wrote it up.

During the last two days of June, a favorable synoptic weather pattern brought extreme heat to portions of northeast Iowa as ample moisture resulted in remarkably high dewpoints. Consequently, heat indices soared well above 100 degrees with numerous locations seeing heat indices of 110 to 115 degrees or even higher in some locations. June 29th was the hottest day but extreme heat persisted into the 30th where heat indices in excess of 100 degrees were still common.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS La Crosse, WI wrote its last area forecast discussion before the first event at Jun 29, 5:06 AM CST, 6 hours 54 minutes earlier.

Area forecast discussion, Jun 29, 5:06 AM CST, 6 hours 54 minutes before
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Hazardous weather outlook, Jun 29, 12:35 AM CST, 11 hours 25 minutes before
Hazardous Weather Outlook
National Weather Service La Crosse WI
135 AM CDT Mon Jun 29 2026

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ029-032>034-
041>044-053>055-061-301100-
Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-
Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-Clark-
Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-Vernon-
Crawford-Richland-Grant-
135 AM CDT Mon Jun 29 2026

This Hazardous Weather Outlook is for portions of north central
Iowa...northeast Iowa...southeast Minnesota...central Wisconsin...
southwest Wisconsin and west central Wisconsin.

.DAY ONE...Today and Tonight

An Extreme Heat Warning remains in effect from 8 am today to 9 pm
Tuesday. Dangerously hot conditions with heat index values of 100
to 110 are expected.

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors. Do not leave
young children and pets in unattended vehicles. Car interiors will
reach lethal temperatures in a matter of minutes.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Daytime heat index values will reach above 100 degrees through at
least mid-week.

Multiple rounds of storms could impact the region this week, some
of which could be severe. However, confidence in the location and
severity of these storms is low at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed tonight in southeast Minnesota
and northeast Iowa.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

WIZ017-301100-
Taylor-
135 AM CDT Mon Jun 29 2026

This Hazardous Weather Outlook is for portions of north central
Wisconsin.

.DAY ONE...Today and Tonight

A Heat Advisory remains in effect from 8 am today to 9 pm
Tuesday. Heat index values of 95 to 105 are expected.

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors. Do not leave
young children and pets in unattended vehicles. Car interiors will
reach lethal temperatures in a matter of minutes.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Daytime heat index values will reach above 95 degrees through at
least mid-week.

Multiple rounds of storms could impact the region this week, some
of which could be severe. However, confidence in the location and
severity of these storms is low at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed tonight in north-central
Wisconsin.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Boyne

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

8 excessive heat. Local standard time, as filed.

Excessive Heat, Allamakee

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Allamakee forecast zone
Reported by
AWOS
Coordinates
43.284, -91.378 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 110 to 119 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 119 degrees at a RAWS site in the Yellow River State Forest. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Chickasaw

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Chickasaw forecast zone
Reported by
AWOS
Coordinates
43.060, -92.318 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 110 to 116 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 116 degrees in Lawler. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Clayton

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Clayton forecast zone
Reported by
AWOS
Coordinates
42.845, -91.341 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 105 to 111 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 111 degrees in McGregor. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Fayette

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Fayette forecast zone
Reported by
AWOS
Coordinates
42.863, -91.844 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 105 to 109 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 109 degrees in Oelwein. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Floyd

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Floyd forecast zone
Reported by
AWOS
Coordinates
43.060, -92.789 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 107 to 115 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 115 degrees in Charles City. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Howard

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Howard forecast zone
Reported by
AWOS
Coordinates
43.357, -92.317 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 105 to 108 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 108 degrees in Riceville. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Mitchell

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Mitchell forecast zone
Reported by
AWOS
Coordinates
43.356, -92.789 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 110 to 117 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 117 degrees in Osage. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

Excessive Heat, Winneshiek

When
June 29, 12:00 PM CST to June 30, 8:00 PM CST
Where
Winneshiek forecast zone
Reported by
AWOS
Coordinates
43.291, -91.844 (the zone’s center; the record gives no point)

A period of extreme heat moved into the region during the end of June with widespread heat indices over 100 degrees. On June 29th, heat indices ranged from 105 to 111 degrees across the county during the afternoon and early evening. The highest heat index observed in the county was 111 degrees in Decorah. On June 30th, continued heat indices over 100 degrees persisted throughout much of the daytime hours.

What these are

Excessive Heat
Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Iowa in 2026Every state in 2026This day in weather historyWarnings in Iowa, June 2026

Sources

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 2026-10-01. Each event’s entry at NCEI: 1355397, 1355399, 1355401, 1355402, 1355403, 1355406, 1355408, 1355409.