Cold in Iowa, September 21, 1999

Name: Cold in Iowa, September 21, 1999
Start: 1999-09-21T01:00
End: 1999-09-21T07:00
Location: Iowa

September 21, 1999 · NWS DMX · 51 events in 51 counties and zones

S. As skies cleared during the evening of the 20th, temperatures fell quite rapidly.

Where it happened

Every event with a place to put it; 51 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: $15 million
Events: 51

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 DMX wrote it up.

The second major push of cold air of the season moved into Iowa as the seasons first real Arctic high pressure moved into the central U.S. As skies cleared during the evening of the 20th, temperatures fell quite rapidly. Though this was the third time frost occurred in the state, it was the first time temperatures fell below 32 degrees. Readings fell into the mid to upper 20s over much of northern Iowa, and parts of central Iowa, with low 30s over the rest of the state. Several record low temperatures for the date were set as this was one of the earliest occurrences of 32 degrees or lower on record. Crops were about 80% mature at the time of the frost, which limited damage. Visual inspection on the afternoon of the 21st indicated that the frost had indeed caused significant plant damage to crops that had not yet reached maturity. Damage was estimated at about $15,000,000 across the state.

The radar

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

Open the radar archive at this moment

Event by event

51 cold/wind chill. Local standard time, as filed.

Cold/Wind Chill, Adair

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Adair forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.331, -94.471 (the zone’s center; the record gives no point)

Cold/Wind Chill, Adams

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Adams forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.029, -94.699 (the zone’s center; the record gives no point)

Cold/Wind Chill, Appanoose

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Appanoose forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.743, -92.869 (the zone’s center; the record gives no point)

Cold/Wind Chill, Audubon

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Audubon forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.685, -94.906 (the zone’s center; the record gives no point)

Cold/Wind Chill, Black Hawk

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Black Hawk forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.470, -92.309 (the zone’s center; the record gives no point)

Cold/Wind Chill, Boone

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Boone forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.037, -93.932 (the zone’s center; the record gives no point)

Cold/Wind Chill, Bremer

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Bremer forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.775, -92.318 (the zone’s center; the record gives no point)

Cold/Wind Chill, Butler

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Butler forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.732, -92.790 (the zone’s center; the record gives no point)

Cold/Wind Chill, Calhoun

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Calhoun forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.385, -94.640 (the zone’s center; the record gives no point)

Cold/Wind Chill, Carroll

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Carroll forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.036, -94.861 (the zone’s center; the record gives no point)

Cold/Wind Chill, Cass

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Cass forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.332, -94.928 (the zone’s center; the record gives no point)

Cold/Wind Chill, Cerro Gordo

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Cerro Gordo forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.082, -93.261 (the zone’s center; the record gives no point)

Cold/Wind Chill, Clarke

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Clarke forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.029, -93.785 (the zone’s center; the record gives no point)

Cold/Wind Chill, Crawford

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Crawford forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.037, -95.382 (the zone’s center; the record gives no point)

Cold/Wind Chill, Dallas

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Dallas forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Cold/Wind Chill, Davis

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Davis forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.748, -92.410 (the zone’s center; the record gives no point)

Cold/Wind Chill, Decatur

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Decatur forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.738, -93.786 (the zone’s center; the record gives no point)

Cold/Wind Chill, Emmet

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Emmet forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.378, -94.678 (the zone’s center; the record gives no point)

Cold/Wind Chill, Franklin

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Franklin forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.733, -93.262 (the zone’s center; the record gives no point)

Cold/Wind Chill, Greene

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Greene forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.036, -94.397 (the zone’s center; the record gives no point)

Cold/Wind Chill, Grundy

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Grundy forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.402, -92.791 (the zone’s center; the record gives no point)

Cold/Wind Chill, Guthrie

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Guthrie forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.684, -94.501 (the zone’s center; the record gives no point)

Cold/Wind Chill, Hamilton

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Hamilton forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.384, -93.707 (the zone’s center; the record gives no point)

Cold/Wind Chill, Hancock

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Hancock forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.082, -93.734 (the zone’s center; the record gives no point)

Cold/Wind Chill, Hardin

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Hardin forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.384, -93.240 (the zone’s center; the record gives no point)

Cold/Wind Chill, Humboldt

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Humboldt forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.777, -94.207 (the zone’s center; the record gives no point)

Cold/Wind Chill, Jasper

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Jasper forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.686, -93.054 (the zone’s center; the record gives no point)

Cold/Wind Chill, Kossuth

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Kossuth forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.204, -94.207 (the zone’s center; the record gives no point)

Cold/Wind Chill, Lucas

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Lucas forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.029, -93.328 (the zone’s center; the record gives no point)

Cold/Wind Chill, Madison

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Madison forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.331, -94.016 (the zone’s center; the record gives no point)

Cold/Wind Chill, Mahaska

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Mahaska forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.335, -92.641 (the zone’s center; the record gives no point)

Cold/Wind Chill, Marion

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Marion forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.334, -93.099 (the zone’s center; the record gives no point)

Cold/Wind Chill, Marshall

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Marshall forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.036, -92.999 (the zone’s center; the record gives no point)

Cold/Wind Chill, Monroe

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Monroe forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.030, -92.869 (the zone’s center; the record gives no point)

Cold/Wind Chill, Palo Alto

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Palo Alto forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.082, -94.678 (the zone’s center; the record gives no point)

Cold/Wind Chill, Pocahontas

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Pocahontas forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.734, -94.679 (the zone’s center; the record gives no point)

Cold/Wind Chill, Polk

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Polk forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.686, -93.573 (the zone’s center; the record gives no point)

Cold/Wind Chill, Poweshiek

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Poweshiek forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.686, -92.531 (the zone’s center; the record gives no point)

Cold/Wind Chill, Ringgold

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Ringgold forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.735, -94.244 (the zone’s center; the record gives no point)

Cold/Wind Chill, Sac

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Sac forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.386, -95.105 (the zone’s center; the record gives no point)

Cold/Wind Chill, Story

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Story forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.036, -93.465 (the zone’s center; the record gives no point)

Cold/Wind Chill, Tama

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Tama forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.080, -92.532 (the zone’s center; the record gives no point)

Cold/Wind Chill, Taylor

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Taylor forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.737, -94.696 (the zone’s center; the record gives no point)

Cold/Wind Chill, Union

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Union forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.028, -94.242 (the zone’s center; the record gives no point)

Cold/Wind Chill, Wapello

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Wapello forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.031, -92.409 (the zone’s center; the record gives no point)

Cold/Wind Chill, Warren

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Warren forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.334, -93.561 (the zone’s center; the record gives no point)

Cold/Wind Chill, Wayne

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Wayne forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.740, -93.327 (the zone’s center; the record gives no point)

Cold/Wind Chill, Webster

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Webster forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.428, -94.182 (the zone’s center; the record gives no point)

Cold/Wind Chill, Winnebago

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Winnebago forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.378, -93.734 (the zone’s center; the record gives no point)

Cold/Wind Chill, Worth

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Worth forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.377, -93.261 (the zone’s center; the record gives no point)

Cold/Wind Chill, Wright

When: September 21, 1:00 AM CST to 7:00 AM CST
Where: Wright forecast zone
Crop damage: $294,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.733, -93.735 (the zone’s center; the record gives no point)

What these are

Cold/Wind Chill: Cold or wind chill below warning criteria that caused deaths, injuries or damage.

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

The same day elsewhere

Every storm in Iowa in 1999 Every state in 1999 This day in weather history Warnings in Iowa, September 1999

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: 5719034, 5719035, 5719036, 5719037, 5719038, 5719039, 5719040, 5719041, 5719042, 5719043, 5719044, 5719045, 5719126, 5719127, 5719128, 5719129, 5719130, 5719131, 5719132, 5719133, 5719134, 5719135, 5719136, 5719137, 5719138, 5719139, 5719140, 5719141, 5719142, 5719143, 5719144, 5719145, 5719146, 5719147, 5719148, 5719149, 5719150, 5719151, 5719152, 5719153, and more.