Excessive Heat in Missouri, July 10 to 12, 2011

Name: Excessive Heat in Missouri, July 10 to 12, 2011
Start: 2011-07-10T12:00
End: 2011-07-12T18:00
Location: Missouri

July 10 to 12, 2011 · NWS LSX · 7 events in 7 counties and zones

A three day heat wave hit the area from July 10 - 12. High temperatures were in the lower to middle 90s, but very humid conditions pushed the Heat Index into the 105 to 110 range.

Where it happened

Every event with a place to put it; 7 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: 7

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.

A three day heat wave hit the area from July 10 - 12. High temperatures were in the lower to middle 90s, but very humid conditions pushed the Heat Index into the 105 to 110 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 St. Louis, MO wrote its last area forecast discussion before the first event at Jul 10, 11:51 AM CST, 9 minutes earlier.

Area forecast discussion, Jul 10, 11:51 AM CST, 9 minutes before

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Hazardous weather outlook, Jul 10, 3:54 AM CST, 8 hours 6 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
454 AM CDT SUN JUL 10 2011

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-111000-
GREENE IL-MACOUPIN IL-MONTGOMERY IL-BOND IL-FAYETTE IL-CLINTON IL-
MARION IL-WASHINGTON IL-RANDOLPH IL-ADAMS IL-BROWN IL-PIKE IL-
CALHOUN IL-JERSEY IL-MADISON IL-ST. CLAIR IL-MONROE IL-KNOX MO-
LEWIS MO-SHELBY MO-MARION MO-MONROE MO-RALLS MO-PIKE MO-BOONE MO-
AUDRAIN MO-MONITEAU MO-COLE MO-OSAGE MO-CALLAWAY MO-MONTGOMERY MO-
LINCOLN MO-GASCONADE MO-WARREN MO-ST. CHARLES MO-FRANKLIN MO-
ST. LOUIS MO-ST. LOUIS CITY MO-JEFFERSON MO-CRAWFORD MO-
WASHINGTON MO-ST. FRANCOIS MO-STE. GENEVIEVE MO-IRON MO-
MADISON MO-REYNOLDS MO-
454 AM CDT SUN JUL 10 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN AND
CENTRAL MISSOURI AS WELL AS WEST CENTRAL AND SOUTHWEST ILLINOIS.

.DAY ONE...TODAY AND TONIGHT

DANGEROUS LEVELS OF HEAT WILL BEGIN TO SPREAD ACROSS THE REGION
TODAY. PEAK AFTERNOON HEAT INDEX VALUES AROUND 105 DEGREES ARE
EXPECTED THROUGHOUT CENTRAL MISSOURI...WHERE A HEAT ADVISORY IS
NOW IN EFFECT.

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ACROSS PORTIONS OF
EASTERN MISSOURI AND WEST CENTRAL ILLINOIS THIS AFTERNOON AND
TONIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

DANGEROUS HEAT AND HUMIDITY WILL ENCOMPASS THE ENTIRE AREA MONDAY
THROUGH TUESDAY. PEAK HEAT INDEX VALUES WILL RANGE FROM 105 TO 115
DEGREES ON MONDAY AND FROM 105 TO 110 DEGREES ON TUESDAY. A HEAT ADVISORY
IS IN EFFECT FOR THE ENTIRE AREA MONDAY AFTERNOON THROUGH TUESDAY.

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS MONDAY ACROSS NORTHEAST
MISSOURI AND WEST CENTRAL ILLINOIS...WITH A BETTER CHANCE OF
THUNDERSTORMS ACROSS THE ENTIRE AREA ON TUESDAY AND WEDNESDAY.

DANGEROUS HEAT AND HUMIDITY IS EXPECTED TO BUILD BACK ACROSS THE
AREA LATE NEXT WEEK AND WEEKEND...WITH PEAK AFTERNOON HEAT INDEX
VALUES BETWEEN 105 AND 110 DEGREES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT.

GLASS

The radar

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

Open the radar archive at this moment

Event by event

7 excessive heat. Local standard time, as filed.

Excessive Heat, Knox

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Knox forecast zone
Reported by: COOP Observer
Coordinates: 40.128, -92.148 (the zone’s center; the record gives no point)

Excessive Heat, Lewis

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Lewis forecast zone
Reported by: COOP Observer
Coordinates: 40.097, -91.722 (the zone’s center; the record gives no point)

Excessive Heat, Monroe

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Monroe forecast zone
Reported by: COOP Observer
Coordinates: 39.496, -92.001 (the zone’s center; the record gives no point)

Excessive Heat, Pike

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Pike forecast zone
Reported by: COOP Observer
Coordinates: 39.344, -91.171 (the zone’s center; the record gives no point)

Excessive Heat, Ralls

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Ralls forecast zone
Reported by: COOP Observer
Coordinates: 39.528, -91.522 (the zone’s center; the record gives no point)

Excessive Heat, Shelby

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Shelby forecast zone
Reported by: COOP Observer
Coordinates: 39.798, -92.077 (the zone’s center; the record gives no point)

Excessive Heat, Marion

When: July 10, 12:00 PM CST to July 12, 6:00 PM CST
Where: Marion forecast zone
Reported by: AWOS
Coordinates: 39.806, -91.622 (the zone’s center; the record gives no point)

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

Every storm in Missouri in 2011 Every state in 2011 This day in weather history Warnings in Missouri, July 2011

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: 372679, 372680, 372681, 372682, 372683, 372684, 372685.