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Tornado in Union County, South Dakota
24 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.
NCEI records 24 tornado events in Union County, South Dakota, between 1950 and 2026, spread over 18 years.
July is the busiest month, with 9 of the recorded events. The last 20 years account for 3 events against 9 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 1.2% of the 1,947 tornado events recorded in South Dakota; its 5.2 per 100 square miles compares with 2.6 statewide.
By rating: 13 at (E)F0, 7 at (E)F1, 1 at (E)F2, 1 at (E)F3, 0 at (E)F4, 0 at (E)F5 and 2 unrated. Tornadoes before 2007 carry the original Fujita rating.
Compared with South Dakota
| Measure | Union County | South Dakota | US |
|---|---|---|---|
| Tornado events since 1950 | 24 | 1,947 | 81,281 |
| Per 100 square miles | 5.2 | 2.6 | 2.3 |
| Per 10,000 residents | 14.2 | 21.7 | 2.4 |
| Deaths recorded | 0 | 19 | 6,410 |
| Busiest month | July | June | May |
By year
Seasonality
0Feb
0Mar
0Apr
1May
5Jun
4Jul
9Aug
3Sep
0Oct
2Nov
0Dec
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 24 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 |
|---|---|---|---|---|---|---|---|
| 11 May 2014 | Tornado | EF0 | $20K | — | — | — | County |
| 4 Oct 2013 | Tornado | EF1 | $250K | — | — | — | County |
| 4 Oct 2013 | Tornado | EF1 | $200K | — | — | — | County |
| 4 Jun 2005 | Tornado | F0 | — | — | — | — | County |
| 28 May 2004 | Tornado | F0 | — | — | — | — | County |
| 28 May 2004 | Tornado | F0 | — | — | — | — | County |
| 18 Apr 2004 | Tornado | F0 | $10K | — | — | — | County |
| 17 Aug 2001 | Tornado | F0 | — | — | — | — | County |
| 2 Jul 1999 | Tornado | F0 | $5K | — | — | — | County |
| 5 Jul 1994 | Tornado | F0 | $50K | $5K | — | 1 | County |
| 16 Jun 1990 | Tornado | F1 | $2.5M | — | — | — | County |
| 7 Jul 1987 | Tornado | F2 | — | — | — | — | County |
| 28 Jul 1986 | Tornado | F0 | — | — | — | — | County |
| 12 Aug 1985 | Tornado | F1 | $3K | — | — | — | County |
| 22 Jul 1983 | Tornado | F0 | $30 | — | — | — | County |
| 22 Jul 1983 | Tornado | F0 | $250 | — | — | — | County |
| 22 Jul 1983 | Tornado | F0 | $30 | — | — | — | County |
| 22 Jul 1983 | Tornado | F1 | $3K | — | — | — | County |
| 5 Jul 1978 | Tornado | — | — | — | — | — | County |
| 8 Aug 1969 | Tornado | — | — | — | — | — | County |
| 7 Jun 1965 | Tornado | F3 | — | — | — | — | County |
| 8 May 1964 | Tornado | F1 | $3K | — | — | — | County |
| 1 Jun 1963 | Tornado | F0 | $3K | — | — | — | County |
| 27 May 1954 | Tornado | F1 | $3K | — | — | — | County |
Questions and answers
How many tornado events has Union County had?
24 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?
11 May 2014 (Tornado, EF0). Records reach NCEI about 120 days after the month ends.
What was the most damaging tornado event recorded in Union County?
The tornado of 16 Jun 1990, with property damage estimated by NCEI at $2.5M.
How does Union County compare with South Dakota for tornado?
5.2 events per 100 square miles against 2.6 statewide; the county holds 24 of the state's 1,947 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.