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Tornado in Union County, Iowa
42 tornadoes events in the NCEI Storm Events record, 1950 to 2026. Event types counted: Tornado.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. Storm records through 30 Jun 2026.
Union County, Iowa, has 42 tornado events in the NCEI record since 1950, with at least one in 27 different years.
April is the busiest month, with 13 of the recorded events. The last 20 years account for 20 events against 10 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 1.2% of the 3,501 tornado events recorded in Iowa; its 9.9 per 100 square miles compares with 6.3 statewide.
By rating: 17 at (E)F0, 11 at (E)F1, 8 at (E)F2, 1 at (E)F3, 3 at (E)F4, 0 at (E)F5 and 2 unrated. Tornadoes before 2007 carry the original Fujita rating.
Compared with Iowa
| Measure | Union County | Iowa | US |
|---|---|---|---|
| Tornado events since 1950 | 42 | 3,501 | 81,281 |
| Per 100 square miles | 9.9 | 6.3 | 2.3 |
| Per 10,000 residents | 34.9 | 11.0 | 2.4 |
| Deaths recorded | 0 | 100 | 6,410 |
| Busiest month | April | May | May |
By year
Seasonality
0Feb
0Mar
6Apr
13May
7Jun
10Jul
2Aug
0Sep
2Oct
1Nov
1Dec
0
Magnitude distribution
Enhanced Fujita scale wind estimates
- EF0/F0
- 65–85 mph (EF0)
- EF1/F1
- 86–110 mph (EF1)
- EF2/F2
- 111–135 mph (EF2)
- EF3/F3
- 136–165 mph (EF3)
- EF4/F4
- 166–200 mph (EF4)
- EF5/F5
- over 200 mph (EF5)
- Unrated
- no rating recorded
Tornado rating as recorded (Fujita scale before February 2007, Enhanced Fujita after).
Recorded events
All 42 events, most recent first. Magnitude is hail size, tornado rating or wind speed as recorded.
| Date | Event type | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|
| 17 Apr 2025 | Tornado | EF1 | $46K | — | — | — | County |
| 21 May 2024 | Tornado | EF0 | $1K | — | — | — | County |
| 21 May 2024 | Tornado | EF unrated | — | — | — | — | County |
| 26 Apr 2024 | Tornado | EF1 | $25K | — | — | — | County |
| 26 Apr 2024 | Tornado | EF2 | $500K | — | — | — | County |
| 26 Apr 2024 | Tornado | EF2 | $300K | — | — | — | County |
| 26 Apr 2024 | Tornado | EF1 | $50K | — | — | — | County |
| 26 Apr 2024 | Tornado | EF2 | $100K | — | — | — | County |
| 5 Mar 2022 | Tornado | EF unrated | — | — | — | — | County |
| 9 Oct 2018 | Tornado | EF1 | $40K | $1K | — | — | County |
| 27 Apr 2016 | Tornado | EF0 | $3K | — | — | — | County |
| 11 Nov 2015 | Tornado | EF1 | $125K | — | — | — | County |
| 14 Apr 2012 | Tornado | EF2 | $5.0M | — | — | 2 | County |
| 22 Mar 2011 | Tornado | EF0 | — | — | — | — | County |
| 5 Jun 2008 | Tornado | EF1 | $25K | $2K | — | — | County |
| 4 Jun 2008 | Tornado | EF1 | — | — | — | — | County |
| 4 Jun 2008 | Tornado | EF0 | — | — | — | — | County |
| 4 Jun 2008 | Tornado | EF1 | $50K | $5K | — | — | County |
| 4 Jun 2008 | Tornado | EF0 | $5K | — | — | — | County |
| 6 May 2007 | Tornado | EF0 | $75K | — | — | — | County |
| 30 Mar 2006 | Tornado | F0 | $40K | — | — | — | County |
| 30 Mar 2006 | Tornado | F0 | — | — | — | — | County |
| 11 Sep 2003 | Tornado | F0 | $250K | $25K | — | — | County |
| 11 Apr 2001 | Tornado | F2 | $150K | — | — | — | County |
| 8 Apr 1999 | Tornado | F4 | $2.0M | — | — | 1 | County |
| 24 Mar 1996 | Tornado | F0 | $25K | — | — | — | County |
| 27 May 1995 | Tornado | F4 | $3.0M | $80K | — | 2 | County |
| 15 Jul 1992 | Tornado | F1 | $3K | — | — | — | County |
| 24 May 1989 | Tornado | F4 | $25M | — | — | — | County |
| 24 Jun 1987 | Tornado | F0 | $250 | — | — | — | County |
| 26 Jun 1985 | Tornado | F0 | — | — | — | — | County |
| 26 Jun 1985 | Tornado | F0 | — | — | — | — | County |
| 16 Jun 1985 | Tornado | F0 | — | — | — | — | County |
| 3 Jul 1983 | Tornado | F0 | $30 | — | — | — | County |
| 29 Mar 1979 | Tornado | F3 | $2.5M | — | — | 2 | County |
| 7 May 1975 | Tornado | F0 | — | — | — | — | County |
| 19 Apr 1973 | Tornado | F1 | $25K | — | — | — | County |
| 12 Sep 1972 | Tornado | F0 | $25K | — | — | — | County |
| 13 Jun 1972 | Tornado | F2 | $25K | — | — | — | County |
| 26 Apr 1964 | Tornado | F2 | $25K | — | — | — | County |
| 12 Apr 1964 | Tornado | F2 | $250K | — | — | — | County |
| 7 May 1962 | Tornado | F1 | $25K | — | — | — | County |
Questions and answers
How many tornado events has Union County had?
42 events in the NCEI Storm Events record between 1950 and 2026. Reporting of tornadoes became far more complete after 1996, so early decades undercount.
When was the last recorded tornado event in Union County?
17 Apr 2025 (Tornado, EF1). Records reach NCEI about 120 days after the month ends.
What was the most damaging tornado event recorded in Union County?
The tornado of 24 May 1989, with property damage estimated by NCEI at $25M.
How does Union County compare with Iowa for tornado?
9.9 events per 100 square miles against 6.3 statewide; the county holds 42 of the state's 3,501 recorded events.
Provenance
NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026, public domain. County-recorded events plus zone-recorded events whose forecast zone is named for the county (marked "Forecast zone"). Population and area from the US Census Bureau (2021). Built 1 Oct 2026. See the methodology, the Tornado hub and the county page.