Wisconsin, 2026

Excessive Heat in Wisconsin, June 30, 2026

June 30, 2026 · NWS MKX · 20 events in 20 counties and zones

A hot and humid air mass setup over southern Wisconsin in late June. Low temperatures struggled to get into the 70s while high temperatures in the 90s combined with high dew points led to heat indices reaching the 105F-110F range.

Where it happened

Every event with a place to put it; 20 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
20

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 MKX wrote it up.

A hot and humid air mass setup over southern Wisconsin in late June. Low temperatures struggled to get into the 70s while high temperatures in the 90s combined with high dew points led to heat indices reaching the 105F-110F range.

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 Milwaukee, WI wrote its last area forecast discussion before the first event at Jun 30, 5:46 AM CST, 6 hours 14 minutes earlier.

Area forecast discussion, Jun 30, 5:46 AM CST, 6 hours 14 minutes before
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Hazardous weather outlook, Jun 30, 5:51 AM CST, 6 hours 9 minutes before
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The radar

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

Open the radar archive at this moment

Event by event

20 excessive heat. Local standard time, as filed.

Excessive Heat, Dane

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Dane forecast zone
Reported by
AWSS
Coordinates
43.067, -89.418 (the zone’s center; the record gives no point)

Peak heat index:|108F-Cottage Grove|106F-Sun Prairie.

Excessive Heat, Columbia

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Columbia forecast zone
Reported by
AWSS
Coordinates
43.467, -89.334 (the zone’s center; the record gives no point)

Peak heat index:|106F-Lodi|105F-Pardeeville.

Excessive Heat, Dodge

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Dodge forecast zone
Reported by
AWSS
Coordinates
43.416, -88.707 (the zone’s center; the record gives no point)

Peak heat index:|107F-Beaver Dam|106F-Horicon.

Excessive Heat, Fond du Lac

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Fond du Lac forecast zone
Reported by
ASOS
Coordinates
43.754, -88.488 (the zone’s center; the record gives no point)

Peak heat index:|107F-Taycheedah|106F-Fond du Lac.

Excessive Heat, Green

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Green forecast zone
Reported by
ASOS
Coordinates
42.680, -89.602 (the zone’s center; the record gives no point)

Peak heat index:|106F Estimated.

Excessive Heat, Green Lake

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Green Lake forecast zone
Reported by
ASOS
Coordinates
43.800, -89.045 (the zone’s center; the record gives no point)

Peak heat index:|109F Berlin.

Excessive Heat, Iowa

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Iowa forecast zone
Reported by
ASOS
Coordinates
43.001, -90.135 (the zone’s center; the record gives no point)

Peak heat index:|106F Barneveld.

Excessive Heat, Jefferson

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Jefferson forecast zone
Reported by
AWOS
Coordinates
43.021, -88.776 (the zone’s center; the record gives no point)

Peak heat index:|109F Watertown.

Excessive Heat, Kenosha

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Kenosha forecast zone
Reported by
AWOS
Coordinates
42.573, -87.840 (the zone’s center; the record gives no point)

Peak heat index:|110F Pleasant Prairie|108F Kenosha.

Excessive Heat, Lafayette

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Lafayette forecast zone
Reported by
AWOS
Coordinates
42.661, -90.132 (the zone’s center; the record gives no point)

Peak heat index:|105F Estimated.

Excessive Heat, Marquette

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Marquette forecast zone
Reported by
AWOS
Coordinates
43.820, -89.399 (the zone’s center; the record gives no point)

Peak heat index:|105F Estimated.

Excessive Heat, Milwaukee

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Milwaukee forecast zone
Reported by
ASOS
Coordinates
43.022, -87.929 (the zone’s center; the record gives no point)

Peak heat index:|110F Butler|106F Mitchell Airport.

Excessive Heat, Ozaukee

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Ozaukee forecast zone
Reported by
ASOS
Coordinates
43.403, -87.891 (the zone’s center; the record gives no point)

Peak heat index:|105F Estimated.

Excessive Heat, Racine

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Racine forecast zone
Reported by
ASOS
Coordinates
42.730, -87.812 (the zone’s center; the record gives no point)

Peak heat index:|110F Wind Lake|108F Burlington|106F Racine.

Excessive Heat, Rock

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Rock forecast zone
Reported by
ASOS
Coordinates
42.671, -89.072 (the zone’s center; the record gives no point)

Peak heat index:|106F Janesville.

Excessive Heat, Sauk

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Sauk forecast zone
Reported by
ASOS
Coordinates
43.427, -89.948 (the zone’s center; the record gives no point)

Peak heat index:|105F Reedsburg|105F Lone Rock.

Excessive Heat, Sheboygan

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Sheboygan forecast zone
Reported by
ASOS
Coordinates
43.756, -87.800 (the zone’s center; the record gives no point)

Peak heat index:|110F Plymouth|106F Sheboygan|105F Random Lake.

Excessive Heat, Walworth

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Walworth forecast zone
Reported by
ASOS
Coordinates
42.669, -88.542 (the zone’s center; the record gives no point)

Peak heat index:|110F Genoa City|105F East Troy.

Excessive Heat, Washington

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Washington forecast zone
Reported by
AWSS
Coordinates
43.369, -88.231 (the zone’s center; the record gives no point)

Peak heat index:|109F Allenton|109F Jackson|106F Colgate.

Excessive Heat, Waukesha

When
June 30, 12:00 PM CST to 8:00 PM CST
Where
Waukesha forecast zone
Reported by
ASOS
Coordinates
43.018, -88.304 (the zone’s center; the record gives no point)

Peak heat index:|110F Muskego|108F Mukwonago|107F Eagle|105F New Berlin|105F Waukesha.

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 Wisconsin in 2026Every state in 2026This day in weather historyWarnings in Wisconsin, 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: 1353852, 1353854, 1353855, 1353857, 1353859, 1353860, 1353862, 1353863, 1353864, 1353865, 1353866, 1353867, 1353869, 1353870, 1353871, 1353872, 1353873, 1353875, 1353876, 1353877.