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Tornado in Clay County, South Dakota
31 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 31 tornado events in Clay County, South Dakota, between 1950 and 2026, spread over 18 years.
June is the busiest month, with 18 of the recorded events. The last 20 years account for 3 events against 13 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 1.6% of the 1,947 tornado events recorded in South Dakota; its 7.5 per 100 square miles compares with 2.6 statewide.
By rating: 15 at (E)F0, 7 at (E)F1, 6 at (E)F2, 0 at (E)F3, 0 at (E)F4, 0 at (E)F5 and 3 unrated. Tornadoes before 2007 carry the original Fujita rating.
Compared with South Dakota
| Measure | Clay County | South Dakota | US |
|---|---|---|---|
| Tornado events since 1950 | 31 | 1,947 | 81,281 |
| Per 100 square miles | 7.5 | 2.6 | 2.3 |
| Per 10,000 residents | 20.5 | 21.7 | 2.4 |
| Deaths recorded | 0 | 19 | 6,410 |
| Busiest month | June | June | May |
By year
Seasonality
0Feb
0Mar
0Apr
1May
8Jun
18Jul
1Aug
2Sep
1Oct
0Nov
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 31 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 |
|---|---|---|---|---|---|---|---|
| 15 May 2021 | Tornado | EF unrated | — | — | — | — | County |
| 29 May 2008 | Tornado | EF1 | — | — | — | — | County |
| 29 May 2008 | Tornado | EF1 | $100K | — | — | — | County |
| 29 May 2004 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F1 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 24 Jun 2003 | Tornado | F0 | — | — | — | — | County |
| 3 Jun 2000 | Tornado | F0 | — | — | — | — | County |
| 16 Jun 1992 | Tornado | F0 | $3K | — | — | — | County |
| 16 Jun 1990 | Tornado | F1 | $2.5M | — | — | — | County |
| 20 May 1988 | Tornado | F0 | — | — | — | — | County |
| 28 Jul 1986 | Tornado | F0 | — | — | — | — | County |
| 21 Jun 1986 | Tornado | F1 | $3K | — | — | — | County |
| 12 Aug 1985 | Tornado | F1 | $3K | — | — | — | County |
| 20 Apr 1985 | Tornado | F1 | $25K | — | — | — | County |
| 11 Jun 1984 | Tornado | F2 | $25K | — | — | — | County |
| 26 Sep 1981 | Tornado | F2 | $25K | — | — | — | County |
| 23 Jun 1981 | Tornado | F0 | — | — | — | — | County |
| 29 May 1980 | Tornado | F0 | — | — | — | — | County |
| 15 Jun 1970 | Tornado | — | — | — | — | — | County |
| 13 Jun 1968 | Tornado | — | — | — | — | — | County |
| 16 Aug 1967 | Tornado | F2 | $25K | — | — | — | County |
| 22 May 1966 | Tornado | F0 | — | — | — | — | County |
| 7 Jun 1965 | Tornado | F2 | — | — | — | — | County |
| 7 Jun 1965 | Tornado | F2 | — | — | — | — | County |
| 8 May 1965 | Tornado | F2 | $25K | — | — | — | County |
Questions and answers
How many tornado events has Clay County had?
31 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 Clay County?
15 May 2021 (Tornado, EF unrated). Records reach NCEI about 120 days after the month ends.
What was the most damaging tornado event recorded in Clay County?
The tornado of 16 Jun 1990, with property damage estimated by NCEI at $2.5M.
How does Clay County compare with South Dakota for tornado?
7.5 events per 100 square miles against 2.6 statewide; the county holds 31 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.