Excessive Heat in Wisconsin

Events

341

Deaths

18

Injuries

48

Damage

$76,000

• Excessive Heat in Wisconsin, July 2 to 6, 20129 deaths · 20 eventsA hot air mass settled over southern Wisconsin to start the month of July, bringing 100-degree heat to many locations for multiple days between July 2nd and July 6th.
• Excessive Heat in Wisconsin, July 17 to 21, 20113 deaths · 40 injured · 13 eventsA dome of hot and humid air over the southern and central Plains built northward into the Upper Midwest from July 17th through July 21st.
• Excessive Heat in Wisconsin, July 17 to 20, 20112 deaths · 8 injured · $76,000 · 13 eventsWarm and humid air invaded western Wisconsin on July 17th and remained in place for the next three days. Two people perished as a result of the excessive heat and at least eight other were treated for heat related illnesses.
• Excessive Heat and Heat in Wisconsin, June 14 to 15, 20222 deaths · 20 eventsPersistent southwest winds brought hot and humid conditions to southern WI. Heat index values well over 100 degrees occurred. Cooling centers were opened in some communities. Two heat related fatalities occurred in Milwaukee.
• Excessive Heat and Heat in Wisconsin, July 19 to 20, 201939 injured · 20 eventsPersistent southwest winds and the passage of a warm front brought a heat wave to southern WI. The Milwaukee and Madison areas did experience an influx of emergency room visits due to heat exhaustion and/or heat stroke.
• Excessive Heat in Wisconsin, July 1 to 7, 20122 deaths · 1 eventA large ridge of high pressure built across the Upper Midwest during the first week of July. This resulted in a combination of high humidity levels and temperatures, leading to two heat-related deaths on July 1 and July 5. Both were in Barron County of west central Wisconsin.
• Excessive Heat and Heat in Wisconsin, August 26 to 27, 202431 eventsLight southerly winds and a strong upper high pressure area brought hot and humid conditions to southern WI. Heat index values reached 100-112 degrees Fahrenheit. Cooling centers were opened in urban areas.
• Excessive Heat and Heat in Wisconsin, August 23 to 24, 202323 eventsWesterly winds brought a very hot and humid air mass into southern WI ahead of a slow moving cold front. Extreme heat index values were observed over much of southern WI for two days.
• Excessive Heat and Heat in Wisconsin, June 29 to 30, 201820 eventsTwo to three days of hot and humid conditions produced heat index values in the 100's. Numerous cooling centers were opened by local communities throughout southern WI. Some public swimming pools hours were extended due to the heat.
• Excessive Heat and Heat in Wisconsin, June 21, 202220 eventsBreezy southwest winds ahead of an approaching cold front brought a hot and humid air mass into southern WI. Maximum heat index values reached the lower 100's.
• Excessive Heat and Heat in Wisconsin, June 21 to 23, 202520 eventsPersistent southwest winds pumped hot and humid air into southern WI for a 3 day period. Heat index values rose into the 100s during the day and only dropped into the 70s at night. Cooling centers were opened in urban areas.
• Excessive Heat and Heat in Wisconsin, June 29, 202620 eventsA 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.
• Excessive Heat in Wisconsin, June 30, 202620 eventsA 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.
• Excessive Heat in Wisconsin, June 29 to 30, 202616 eventsA warm front lifted north through the region Monday morning (6/29) allowing daytime temperatures to soar into the upper 80s to lower 90s with dew points in the middle to upper 70s Monday (6/29) afternoon across central and portions of east-central Wisconsin.
• Excessive Heat in Wisconsin, June 21 to 23, 202513 eventsA warm front lifted north through the region late Friday night (6/20) into early Saturday morning (6/21) allowing daytime temperatures to soar into the lower to middle 90s with dew points in the middle to upper 70s Saturday (6/21) and Sunday (6/22) afternoon.
• Excessive Heat in Wisconsin, June 29 to 30, 202613 eventsDuring the last two days of June, a favorable synoptic weather pattern brought extreme heat to western Wisconsin as ample moisture resulted in remarkably high dewpoints.
• Excessive Heat in Wisconsin, June 29 to 30, 201811 eventsJune ended with two days of excessive heat across western Wisconsin. Heat indices topped out between 105 and 115 on both June 29th and 30th, although the high heat indices were more widespread on the 29th.
• Excessive Heat in Wisconsin, July 18 to 20, 201911 eventsWestern Wisconsin sweltered under two days of excessive heat in the middle of July. Heat indices topped out between 100 and 110 on July 18th and 105 and 120 on July 19th.
• Excessive Heat in Wisconsin, August 26, 202411 eventsAfter a relatively mild summer, a period of excessive heat impacted much of the region prompting air temperatures to reach well above 90 degrees during the afternoon on August 26th.
• Excessive Heat in Wisconsin, July 3 to 6, 201210 eventsA hot air mass settled over Wisconsin in early July, bringing highs of 100 degrees or hotter to central Wisconsin from July 4th through July 6th. Relative humidities were relatively low, but heat indices still managed to reach the 100 and 110 range.
• Excessive Heat in Wisconsin, August 23, 202310 eventsA strong warm front allowed temperatures to rise into the 90s to low 100s with dew points in the middle 70s to lower 80s across much of central and east-central Wisconsin on Wednesday (8/23).
• Excessive Heat in Wisconsin, August 22 to 24, 202310 eventsWhile parts of the 2023 summer had warm to hot temperatures, it took until mid to late August for the combination of hot temperatures and higher humidity levels to build a heat wave.
• Excessive Heat in Wisconsin, July 18 to 20, 20119 eventsA large ridge of high pressure expanded across the Upper Midwest and allowed for a stagnant pattern, and eventually oppressive heat and humidity to develop. Maximum heat index values varied from 108 to 116.
• Excessive Heat and Heat in Wisconsin, August 6, 20229 eventsHeat and high humidity along a warm front settled over far southern WI. Heat index values rose into the lower 100's.
• Excessive Heat and Heat in Wisconsin, July 20, 20168 eventsVery warm air in the 80s and 90s and dew point temperatures in the lower and middle 70s resulted in heat index readings of 95 to 105 degrees across much of northwest Wisconsin on July 20th. The highest readings were for areas closer to the Minnesota border.

Excessive Heat everywhereEvery kind of event in Wisconsin

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.