Excessive Heat in Illinois

Events

1,227

Deaths

62

Injuries

21

Damage

$750,000

• Excessive Heat in Illinois, July 4 to 7, 201225 deaths · $750,000 · 18 eventsNorthern Illinois experienced an intense heat wave during the first week of July. High temperatures at Chicago O'Hare Airport reached 102 on the 4th, 103 on the 5th and 6th and 98 on the 7th.
• Excessive Heat and Heat in Illinois, July 16 to 20, 20136 deaths · $25,000 · 3 eventsFrom July 14th through the 21st, temperatures climbed into the upper 80s to mid 90s while overnight lows stayed in the 70s. The warmest stretch ran from the 17th through the 19th.
• Excessive Heat in Illinois, June 22 to 25, 20095 deaths · 3 eventsTemperatures climbed to near 90 on June 22nd and into the middle 90s on June 23rd, 24th and 25th with afternoon heat indices in the upper 90s. Overnight low temperatures ranged from the lower to middle 70s.
• Excessive Heat in Illinois, July 17 to 31, 20114 deaths · 14 eventsA major Heat Wave hit the area from July 17th and continued into early August. High temperatures ranged from the lower 90s to around 100. Low temperatures at night were generally around 80. The Heat Index ranged from around 105 to 115. There were four deaths reported. Two in St.
• Excessive Heat in Illinois, June 14 to 18, 20074 deaths · 1 eventHigh temperatures climbed into the lower 90s during the middle of June. Four people died from heat stress.
• Excessive Heat in Illinois, August 4 to 16, 20073 deaths · 9 injured · 14 eventsThe first and only real Heat Wave of the summer began on August 4th and lasted through August 16th. High temperatures were consistently from the middle 90s to around 100 with the Heat Index from 105 to 110 degrees. Two deaths were reported in Madison County and one in St.
• Excessive Heat in Illinois, July 1 to 8, 20122 deaths · 17 eventsThe Heat Wave that began in late June continued into the first week of July, finally breaking on on July 9. Numerous high temperature records were set during the event. Quincy, IL had high temperatures from July 2 - July 7 of 101, 99, 101, 103, 105, and 105.
• Excessive Heat in Illinois, July 10 to 12, 20112 deaths · 14 eventsA short but intense Heat Wave hit Southwest Illinois from July 10 - 12. High temperatures were in the upper 90s to around 100 with the Heat Index from 110 - 115. Belleville had a high Heat Index of 121 on July 12. There were two deaths reported.
• Excessive Heat in Illinois, July 20 to 24, 20112 deaths · 2 eventsA large upper-level ridge of high pressure brought oppressively hot and humid conditions to central Illinois from July 17th through July 24th. Afternoon high temperatures reached the middle to upper 90s, while heat index readings climbed into the 105 to 115 degree range.
• Excessive Heat in Illinois, July 17 to 21, 20192 deaths · 2 eventsA large ridge of high pressure building over the Midwest brought a period of hot and humid weather to central Illinois from July 17th through July 21st.
• Excessive Heat in Illinois, July 1 to 7, 20121 death · 35 eventsAn extended period of excessive heat and humidity occurred across central and southeast Illinois from June 29th through July 7th. Afternoon high temperatures ranged from 95 to 105 degrees...while overnight lows generally remained in the 70s.
• Excessive Heat in Illinois, July 27 to 28, 20231 death · 35 eventsA two-day stretch of excessive heat impacted much of the Midwest, including all of central and southeastern Illinois. High temperatures climbed into the 90s while dewpoint temperatures were in the upper 70s or low 80s, resulting in heat indices of 100 to 115 degrees.
• Excessive Heat and Heat in Illinois, June 13 to 15, 20221 death · 22 eventsHot and humid conditions developed across northern Illinois during the afternoon of June 13th and continued through the afternoon of June 15th. High temperatures reached the middle to upper 90s on all three days. Midway Airport reached 100 degrees on June 14th and June 15th.
• Excessive Heat in Illinois, August 1 to 3, 20111 death · 17 eventsThe Heat Wave that started on July 17th continued into the first three days of August. Many locations across the area topped 100 degrees on the 1st and 2nd with the Heat Index ranging from 105 to 110. Quincy set a record high on August 2nd hitting 102 degrees.
• Excessive Heat in Illinois, July 16 to 19, 20121 death · 17 eventsExcessive heat returned to the area. High temperatures ranged from 100 - 106 with the Heat Index a few degrees higher. There was one heat related death reported in St. Clair County, Il, in East St. Louis. A homeless man was found in an abandoned home.
• Excessive Heat in Illinois, July 17 to 28, 20111 death · 3 eventsA heat wave extending from July 17 through July 28 hit the area. There were a couple of days the heat broke, but for the most part it was continuous. High temperatures ranged from the lower to upper 90s with the Heat Index ranging form 105 to 110.
• Excessive Heat in Illinois, June 17 to 27, 20091 death · 2 eventsThe first Heat Wave of the summer hit the Metro East area from June 17th through June 27th. Heat Index values averages around 105 degrees during the period, although there was one day, the 20th in which the Heat Index cooled to around 100.
• Excessive Heat in Illinois, July 8 to 10, 20071 death · 1 eventHigh temperatures reached the mid 90s on July 8th and July 9th and near 90 on July 10th. One person died from heat stress.
• Excessive Heat in Illinois, June 19, 20091 death · 1 eventA 29 year old Griggsville, IL resident died of heat stroke while working at a construction site in Valley City on June 19. High temperatures in the area were in the middle 90s with the Heat Index from 100 - 105.
• Excessive Heat in Illinois, August 9 to 10, 20091 death · 1 eventHigh temperatures reached the lower 90s on August 9th and the middle 80s on August 10th. A 54 year old man suffered a heat stroke in Chicago and died.
• Excessive Heat in Illinois, August 12, 20101 death · 1 eventHigh temperatures reached the lower to middle 90s across much of northern Illinois.
• Excessive Heat in Illinois, August 9 to 15, 201010 injured · 19 eventsA strong and very persistent high in the upper levels of the atmosphere was responsible for seven consecutive days of heat indices at or above 105 degrees.
• Excessive Heat and Heat in Illinois, July 1 to 5, 201838 eventsThe prolonged period of hazardous heat and humidity that began on June 29th persisted through the first several days of July. The most dangerous heat index values occurred on July 5th, when afternoon heat indices peaked around 110 degrees.
• Excessive Heat and Heat in Illinois, July 27 to 29, 202338 eventsA heat wave brought three consecutive days of heat indices near or above 105 degrees. Excessive heat occurred on the afternoons of the 27th and 28th, when heat indices peaked around 110 degrees. Peak heat indices ranged from 103 to 109 degrees on the 29th.
• Excessive Heat in Illinois, August 3 to 4, 20102 injured · 19 eventsExcessively high heat indices were recorded in the late morning and afternoon hours of both the 3rd and 4th. On the 3rd, the heat index peaked at 118 degrees at the Carbondale airport. Similar values were measured elsewhere in southern Illinois.

Excessive Heat everywhereEvery kind of event in Illinois

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.