Heat, Marquette
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Marquette forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.820, -89.399 (the zone’s center; the record gives no point)
Heat in Wisconsin, July 31, 2001
This was the second period of excessive heat, during the summer of 2001, to affect parts of south-central and southeast Wisconsin. Afternoon heat index values on the 31st reached 105 to 110 for several hours, while they stayed in the 85 to 100 range during the evening hours.
Where it happened
Every event with a place to put it; 17 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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 17
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.
This was the second period of excessive heat, during the summer of 2001, to affect parts of south-central and southeast Wisconsin. Afternoon heat index values on the 31st reached 105 to 110 for several hours, while they stayed in the 85 to 100 range during the evening hours. maximum afternoon air temperatures were in the lower to mid 90s, with surface dewpoints in the lower to mid 70s. Although official numbers are not available, several people were probably treated at hospitals due to the affects of heat exhaustion. For July 31, 2001, Madison (Dane Co.) recorded a maximum air temperature of 95, tying the daily record set back in 1988. Ft. Atkinson (Jefferson Co.) and Wisconsin Dells (Columbia Co.) both registered a high of 97. The 31st was the hottest day, to date, for the summer of 2001. Several utility companies reported new daily record demands for electricity, and public swimming pools reported large numbers of swimmers. The excessive heat on the 31st persisted to about 9pm on August 1, 2001.
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 Jul 31, 2:14 AM CST, 8 hours 46 minutes earlier.
Area forecast discussion, Jul 31, 2:14 AM CST, 8 hours 46 minutes before
AREA FORECAST DISCUSSION...CORRECTION TO ADD FOG ADVY AT BOTTOM...
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
314 AM CDT TUE JUL 31 2001
FORECAST FOCUS ON HEAT INDICIES TODAY AND WEDNESDAY...AS WELL AS
PRECIPITATION CHANCES WEDNESDAY AND WEDNESDAY NIGHT.
MODELS ARE POINTING TOWARDS WARMER TEMPERATURES AND HIGHER DEWPOINTS
THAN PREVIOUS RUNS. MODELS IN PRETTY GOOD AGREEMENT WITH HIGH
TEMPERATURES IN THE MID 90S IN CENTRAL AND WESTERN ZONES WITH
DEWPOINTS IN THE LOW TO MID 70S. THIS COMBINATION OF HEAT AND
HUMIDITY GIVES US HEAT INDEX VALUES AROUND 105. WILL ISSUE AN
EXCESSIVE HEAT WARNING FOR THIS AFTERNOON AND EVENING AS HEAT
INDEX VALUES WILL NOT LOWER MUCH UNTIL SUNDOWN. WILL LEAVE THE LAKE
ZONES OUT OF THE WARNING WITH THE LAKE BREEZE PROVIDING RELIEF IN THE
AFTERNOON.
MORNING PRECIPITATION...ASSOCIATED WITH 500 MB VORTICITY MAXIMUM...
IS FORCAST TO WEAKEN AND MOVE NORTHEAST BY THE AFTERNOON HOURS. WILL
LEAVE PRECIPITATION OUT OF THE FORECAST THIS AFTERNOON AND TONIGHT.
EVEN THOUGH THE ATMOSPHERE IS UNSTABLE...CIN VALUES OF 50 J/KG AND
BETTER...AS WELL AS 700 MB TEMPERATURES OF 11 TO 12 DEGREES CELSIUS
SHOULD BE SUFFICIENT TO CAP THE ATMOSPHERE. THE ONLY PROBLEM WILL BE
IF THE MCS OVER THE EASTERN DAKOTAS MOVES THROUGH WISCONSIN THIS
AFTERNOON AS SUGGESTED BY THE 06Z ETA. WILL NOT INCLUDE THIS
FEATURE YET AS THE MODEL WEAKENS IT AS IT APPROACHES THE AREA.
WEDNESDAY HAS THE POTENTIAL TO BE HOT IN THE EASTERN ZONES WITH A
SOUTHWEST FLOW PREVENTING THE LAKE BREEZE FROM KICKING IN. HOWEVER
PRECIPITATION CHANCES LOOK BETTER AS THE CIN LOWERS...THE CAPE
RISES...AND A TRIGGER MOVES THROUGH THE CWA IN THE FORM OF A COLD
FRONT FROM THE NORTHERN PLAINS. THE CONVECTION IS EXPECTED TO FIRE
UP IN THE WESTERN ZONES BY EARLY AFTERNOON...KEEPING TEMPERATURES
THERE BELOW WARNING CRITERIA. HOWEVER EASTERN ZONES WILL BE CUTTING
IT CLOSE WITH HEAT INDEX VALUES IN THE LOW 100S. WILL BET THAT
BLOWOFF FROM THE CONVECTION OUT TO THE WEST WILL BLOCK SOME
SUNLIGHT OUT AND KEEP HEAT INDEX VALUES FROM REACHING 105 ON
WEDNESDAY.
THE FRONTAL BOUNDARY LAYS UP OVER THE CWA WEDNESDAY NIGHT...WITH A
CONTINUED CHANCE FOR PRE/CIPITATION WITH THE TRIGGER AND UNSTABLE AIR
IN PLACE.
COORDINATION WITH ARX...CHI.
.MKX...EXCESSIVE HEAT WARNING THIS AFTERNOON AND EVENING
ZNS..46..47..51..56>59..62>65..67>70.
KURIMSKIThe radar
The national radar mosaic for the moment the first event began.
Event by event
17 heat. Local standard time, as filed.
Heat, Green Lake
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Green Lake forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.800, -89.045 (the zone’s center; the record gives no point)
Heat, Fond du Lac
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Fond du Lac forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.754, -88.488 (the zone’s center; the record gives no point)
Heat, Sheboygan
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Sheboygan forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.756, -87.800 (the zone’s center; the record gives no point)
Heat, Sauk
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Sauk forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.427, -89.948 (the zone’s center; the record gives no point)
Heat, Columbia
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Columbia forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.467, -89.334 (the zone’s center; the record gives no point)
Heat, Dodge
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Dodge forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.416, -88.707 (the zone’s center; the record gives no point)
Heat, Washington
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Washington forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.369, -88.231 (the zone’s center; the record gives no point)
Heat, Iowa
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Iowa forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.001, -90.135 (the zone’s center; the record gives no point)
Heat, Dane
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Dane forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.067, -89.418 (the zone’s center; the record gives no point)
Heat, Jefferson
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Jefferson forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.021, -88.776 (the zone’s center; the record gives no point)
Heat, Waukesha
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Waukesha forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 43.018, -88.304 (the zone’s center; the record gives no point)
Heat, Lafayette
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Lafayette forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 42.661, -90.132 (the zone’s center; the record gives no point)
Heat, Green
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Green forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 42.680, -89.602 (the zone’s center; the record gives no point)
Heat, Rock
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Rock forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 42.671, -89.072 (the zone’s center; the record gives no point)
Heat, Walworth
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Walworth forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 42.669, -88.542 (the zone’s center; the record gives no point)
Heat, Kenosha
- When
- July 31, 11:00 AM CST to 11:59 PM CST
- Where
- Kenosha forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 42.573, -87.840 (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
- Heat in Wisconsin, July 31, 2001
- Flash Flood and Damaging Wind in Arizona, July 31, 2001
- Heat in Wisconsin, July 31, 2001
- Heavy Rain in Florida, July 31, 2001
- Tornado and Flash Flooding in Minnesota, July 31, 2001
- Hail and Damaging Winds in Minnesota, July 31, 2001
- Tornado and Hail in Minnesota, July 31, 2001
- Hail and Damaging Winds in Nebraska, July 31, 2001
- Damaging Winds in North Dakota, July 31, 2001
- Damaging Wind in Louisiana, July 31, 2001
- Cold in New Jersey, July 31, 2001
- Flash Flood and Hail in North Dakota, July 31, 2001
More
Every storm in Wisconsin in 2001Every state in 2001This day in weather historyWarnings in Wisconsin, July 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: 5259470, 5259471, 5259472, 5259473, 5259474, 5259475, 5259476, 5259477, 5259478, 5259541, 5259542, 5259543, 5259544, 5259545, 5259546, 5259547, 5259548.