Heat in Illinois, August 21 to 22, 2001

Name: Heat in Illinois, August 21 to 22, 2001
Start: 2001-08-21T00:00
End: 2001-08-22T21:00
Location: Illinois

August 21 to 22, 2001 · NWS LSX · 16 events in 16 counties and zones

The last heat wave of the summer hit the area for a couple of days. Temperatures were the hottest of the summer with highs in the middle 90s to around 100.

Where it happened

Every event with a place to put it; 16 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: 16

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 LSX wrote it up.

The last heat wave of the summer hit the area for a couple of days. Temperatures were the hottest of the summer with highs in the middle 90s to around 100. The Heat Index ranged from 105 to 110.

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 St. Louis, MO wrote its last area forecast discussion before the first event at Aug 20, 2:30 PM CST, 9 hours 30 minutes earlier.

Area forecast discussion, Aug 20, 2:30 PM CST, 9 hours 30 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
330 PM CDT MON AUG 20 2001

NWP PROGS STILL SUGGESTING THE DVLPMT OF ELEVATED CNVTN ACR CWA AFT
MIDN TNGT.   ALL MDLS STILL FCSTG AT LEAST 12C 85H DWPTS INTO AREA
BY 12Z TUE...WITH GD BAROCLINICITY PROVIDING THE NEEDED LFT TO GET
STMS GOING.  12Z UA DATA INDICATED THAT THE CNVTN OVR SW MO THIS
MRNG DVLPD WITH VRY LTL LFT...SO THINK STM CVG TNGT SHUD BE GRTR
THAN INDICATED BY MOS OUTPUT.  NGM OUTPUT MORE AGGRESSIVE WITH
PCPN...AND MAY NOT BE TOO BAD JUDGING BY WHAT HAPPENED THIS MRNG.

AS 85H/SFC FNTL BNDRIES LFT NE ON TUE PCPN THRT SHUD END FROM SW TO
NE ACR AREA...REPLACED BY WRMR AND MORE HUMID (IE MORE TYPICAL)
AUGUST AMS.  TEMPS REALLY SOARING THIS AFTN IN THE DRIER AMS OVR
PLAINS...BUT BLV THAT SFC DWPTS IN OUR AREA WL BE SUFFICIENTLY HI TO
KP TEMPS FROM GETTING MUCH WRMR THAT LWR 90S IN SW ZNS.

AFT TUE...ETA WANTS TO CAP AMS OVR MO/S IL AS UPR RDG BUILDS INTO MS
VLY...WHILE AVN AND LAST PART OF NGM RUN HINTS AT SM SHTWV ENERGY
AND COOLER TEMPS AT MID LVLS...ALLOWING PCPN THRT TO CONT.  GIVEN
THE FACT THAT WE ARE HEADING TWD FALL AND THAT FNTL BNDRY WL BE IN
AREA...FEEL ITS PRUDENT TO STAY THE COURSE OF GOING FCST AND CONT
PCPN THRT UNTIL FROPA OCRS.

.STL...NONE
TRUETT

C LST EVE ACRS AREA WILL BE REPLACED BY TEMPS OF 20C BY TUE EVE.
THESE TEMPS ARE THEN FCST BY AVN, OLD MRF RUN AND ECMWF TO HANG ARND
ALL WEEK.

MSTR FCST TO RTRN LTR TNGT WITH ETA AND AVN SMLR IN FCSTG MID 30 KS
SLIDING ACRS E MO.  DRIER AIR FCST TO PSH UP OUT OF THE SW TUE NGT
WITH AVN LTL SLOER WITH DRIER AIR.  WAA PCPN FCST BY MODELS LT TNGT
INTO TUE WITH THE NGM BEING THE MOST WIDESPREAD. CURRENT FCST
REFLCTS THIS SCENERIO WELL AND LTL CHANGE NEEDED.

.STL...NONE

The radar

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

Open the radar archive at this moment

Event by event

16 heat. Local standard time, as filed.

Heat, Adams

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Adams forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.988, -91.188 (the zone’s center; the record gives no point)

Heat, Bond

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Bond forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.887, -89.436 (the zone’s center; the record gives no point)

Heat, Brown

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Brown forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.962, -90.750 (the zone’s center; the record gives no point)

Heat, Calhoun

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Calhoun forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.169, -90.667 (the zone’s center; the record gives no point)

Heat, Clinton

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Clinton forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.607, -89.422 (the zone’s center; the record gives no point)

Heat, Fayette

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Fayette forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.000, -89.024 (the zone’s center; the record gives no point)

Heat, Greene

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Greene forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.356, -90.390 (the zone’s center; the record gives no point)

Heat, Jersey

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Jersey forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.086, -90.357 (the zone’s center; the record gives no point)

Heat, Macoupin

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Macoupin forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.261, -89.924 (the zone’s center; the record gives no point)

Heat, Madison

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Madison forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.830, -89.905 (the zone’s center; the record gives no point)

Heat, Monroe

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Monroe forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.279, -90.177 (the zone’s center; the record gives no point)

Heat, Montgomery

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Montgomery forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.231, -89.479 (the zone’s center; the record gives no point)

Heat, Pike

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Pike forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 39.623, -90.886 (the zone’s center; the record gives no point)

Heat, Randolph

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Randolph forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.052, -89.825 (the zone’s center; the record gives no point)

Heat, St. Clair

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: St. Clair forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.470, -89.928 (the zone’s center; the record gives no point)

Heat, Washington

When: August 21, 12:00 AM CST to August 22, 9:00 PM CST
Where: Washington forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 38.352, -89.410 (the zone’s center; the record gives no point)

What these are

Heat: Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.

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

The same day elsewhere

Every storm in Illinois in 2001 Every state in 2001 This day in weather history Warnings in Illinois, August 2001

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 2026-09-24. Each event’s entry at NCEI: 5263285, 5263286, 5263287, 5263288, 5263289, 5263290, 5263291, 5263292, 5263293, 5263294, 5263295, 5263296, 5263297, 5263298, 5263299, 5263300.