Harrison County, Iowa severe weather history spans 496 recorded events between 1959 and 2026. The dominant hazard is hail, accounting for 43.8% of all recorded events. It ranks #893 nationally and #32 in Iowa.
496
Recorded events
2
Direct deaths
20
Direct injuries
$31.0M
Property damage
The record
What the Harrison County, Iowa severe weather history record shows
Across the archive, Harrison County, Iowa severe weather history averages 7.4 recorded events a year. The busiest stretch on record is the 2000s, with 158 events logged in that decade alone. Roughly 63 events fall before 1990 and 433 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Harrison County, Iowa record is tornado, responsible for 2 direct deaths. The costliest is flash flood, with $15.6M in reported property damage. In total, 7 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Harrison County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Hail | 217 | 0 | $0 | 3 | 1964–2026 |
| Thunderstorm Wind | 209 | 0 | $869K | 93 | 1959–2025 |
| Tornado | 34 | 2 | $4.9M | F3 | 1967–2026 |
| Flood | 15 | 0 | $9.6M | 0 | 2007–2024 |
| Flash Flood | 11 | 0 | $15.6M | 0 | 1996–2024 |
| Heavy Rain | 9 | 0 | $0 | 0 | 2007–2023 |
| Funnel Cloud | 1 | 0 | $0 | 0 | 1998–1998 |
Decade by decade
Harrison County, Iowa severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
39 mapped tornado paths intersect this county: 28 touched down inside it and 11 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2024-04-26 | EF4 | 0 | 4 | 31.9 mi | Crossed in |
| 2008-06-11 | EF3 | 4 | 48 | 13.0 mi | Crossed in |
| 1999-05-16 | EF3 | 2 | 16 | 7.5 mi | Touched down here |
| 2024-04-26 | EF3 | 1 | 3 | 40.3 mi | Crossed in |
| 2024-04-26 | EF3 | 0 | 0 | 19.1 mi | Crossed in |
| 1999-05-16 | EF3 | 0 | 0 | 6.2 mi | Touched down here |
| 1992-06-16 | EF3 | 0 | 3 | 26.0 mi | Touched down here |
| 2023-07-12 | EF2 | 0 | 0 | 9.4 mi | Touched down here |
| 2009-03-23 | EF2 | 0 | 0 | 8.6 mi | Touched down here |
| 1983-05-06 | EF2 | 0 | 0 | 15.0 mi | Touched down here |
Significant events
Deadliest events on record in Harrison County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| May 16, 1999 | Tornado | MISSOURI VLY | 2 | 16 | $1.9M |
| Mar 22, 2011 | Tornado | EUCLID | 0 | 2 | $0 |
| Aug 24, 1990 | Thunderstorm Wind | 0 | 1 | $0 | |
| Jun 30, 1986 | Thunderstorm Wind | 0 | 1 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
The stronger of the 2 tornadoes that ripped through Harrison county the afternoon of 5/16/99 killed 2 people and destroyed 6 homes and a bridge before it dissipated a couple of miles east of Logan. A family of 5 leaving a high school graduation party encountered the tornado on a road around 6 miles northeast of Missouri Valley and took cover in a ditch about the time the path of the tornado widened to a quarter mile. Two of them were killed after their car and a 3-ton combine head were thrown on them. There were also numerous flipped or smashed vehicles in this area.
Thiere was for flooding along the Boyer River. The river gauge at Logan, operated by the USGS, peaked at 25.33 feet at 7 pm on March 13th. Major flood stage is 25 feet. Preliminary information shows this peak is the highest on record. Portions of the town of Missouri Valley flooded from the flood. Highway 30 closed in Woodbine. A levee topped by floodwaters at 296th street in Missouri Valley, on the east side of the levee around 2 miles northeast of town. Also 2 breaches in the levee around Willow Creek. Evacuations took place in Missouri Valley. Property damage totals are for the entire county from flooding of the Boyer River, Willow Creek, and Missouri River.
Forest Service reported up to two dozen culverts washed out and six county roads that were partially or fully washed out. Large trees were washed into fields and there was significant damage to farm fields in several areas in the counties. There are significant areas of crop fields that likely lost in excess of 100 tons per acre from that one heavy rain event. The county estimated the damage to be approximately $400,000-$600,000.
Context
Risk, population and federal disasters
Very Low
FEMA NRI risk rating
14,632
Population (ACS)
$176K
Median home value
24
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| May 21, 2025 | Winter Storm | SEVERE WINTER STORM | DR |
| Jun 24, 2024 | Severe Storm | SEVERE STORMS, FLOODING, STRAIGHT-LINE WINDS, AND TORNADOES | DR |
| May 24, 2024 | Severe Storm | SEVERE STORMS, TORNADOES, AND FLOODING | DR |
| May 14, 2024 | Tornado | SEVERE STORMS AND TORNADOES | DR |
| Mar 23, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
Quick answers
Frequently asked
How many severe weather events have been recorded in Harrison County, Iowa?
496 events are on record between 1959 and 2026, causing 2 direct deaths and $31.0M in property damage.
What is the most common severe weather hazard in Harrison County?
Hail, with 217 recorded events — 43.8% of everything in the archive for this county.
How many tornadoes have crossed Harrison County?
39 mapped tornado paths intersect the county boundary; 28 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Harrison County?
24 federal disaster declarations from FEMA include Harrison County, each tied to a specific incident period.
How risky is Harrison County compared with the rest of the country?
FEMA's National Risk Index rates Harrison County as very low risk, placing it in the 31 percentile of its state for expected annual loss.
Where does the Harrison County, Iowa severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Hardin County 469
- Henry County 304
- Hancock County 318
- Howard County 309
- Hamilton County 438
- Humboldt County 312
Cite this page
“Harrison County, Iowa.” Severe Weather History. severeweatherhistory.com/county/iowa/harrison-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.