Iowa, 1998

Hail in Iowa, May 20, 1998

May 20, 1998 · NWS DMX · 9 events in 4 counties and zones

Thunderstorms fired up during the mid morning hours on the outflow boundary left behind by convection the previous night and early morning. The airmass was quite unstable and the storms became severe quickly.

Where it happened

Every event with a place to put it. 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
$162,000
Crop damage
$74,000
Events
9

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.

Thunderstorms fired up during the mid morning hours on the outflow boundary left behind by convection the previous night and early morning. The airmass was quite unstable and the storms became severe quickly. The main weather feature with the storms was hail. Numerous reports of large hail came in from a four county area, with many of them up go golf ball in size. Hail nearly the size of baseballs fell northwest of Knoxville in Marion County, with one confirmed report of hail over three inches in diameter measured in the town of Hiteman..

The radar

The Des Moines radar (KDMX), 69 km away, was scanning. The volume nearest the first event began at 15:23 UTC.

Open the radar archive at this moment

Event by event

9 hail. Local standard time, as filed.

Hail, Marion

When
May 20, 9:25 AM CST
Where
Marion County, Knoxville
Measured
1 in hail
Property damage
$1,000
Crop damage
$5,000
Coordinates
41.320, -93.100

Hail, Marion

When
May 20, 9:53 AM CST
Where
Marion County, 5 mi NW of Knoxville
Measured
2.5 in hail
Property damage
$10,000
Crop damage
$10,000
Coordinates
41.370, -93.170

Hail, Monroe

When
May 20, 10:05 AM CST
Where
Monroe County, Hiteman
Measured
3.25 in hail
Property damage
$100,000
Crop damage
$25,000
Coordinates
41.070, -92.920

Hail, Wapello

When
May 20, 10:15 AM CST
Where
Wapello County, 8 mi W of Ottumwa
Measured
1.75 in hail
Property damage
$10,000
Crop damage
$10,000
Coordinates
41.020, -92.550

Hail, Wapello

When
May 20, 10:20 AM CST
Where
Wapello County, Blakesburg
Measured
1.75 in hail
Property damage
$20,000
Crop damage
$7,000
Coordinates
40.930, -92.680

Hail, Wapello

When
May 20, 10:20 AM CST
Where
Wapello County, 2 mi W of Ottumwa
Measured
1.75 in hail
Property damage
$10,000
Crop damage
$5,000
Coordinates
41.020, -92.430

Hail, Wapello

When
May 20, 10:24 AM CST
Where
Wapello County, Ottumwa
Measured
1 in hail
Property damage
$3,000
Coordinates
41.020, -92.400

Hail, Wapello

When
May 20, 10:30 AM CST
Where
Wapello County, 1 mi S of Agency
Measured
1.25 in hail
Property damage
$5,000
Crop damage
$7,000
Coordinates
40.970, -92.370

Hail, Mahaska

When
May 20, 10:47 AM CST
Where
Mahaska County, 4 mi S of Rose Hill
Measured
1 in hail
Property damage
$3,000
Crop damage
$5,000
Coordinates
41.270, -92.470

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.

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

The same day elsewhere

More

Every storm in Iowa in 1998Every state in 1998This day in weather historyWarnings in Iowa, May 1998

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: 5645907, 5645908, 5645909, 5646667, 5646668, 5646669, 5646670, 5646671, 5646672.