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Tornado in Knox County, Illinois
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.
Knox County, Illinois, has 31 tornado events in the NCEI record since 1950, with at least one in 22 different years.
June is the busiest month, with 10 of the recorded events. The last 20 years account for 10 events against 11 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 0.9% of the 3,647 tornado events recorded in Illinois; its 4.3 per 100 square miles compares with 6.6 statewide.
By rating: 12 at (E)F0, 10 at (E)F1, 4 at (E)F2, 2 at (E)F3, 0 at (E)F4, 0 at (E)F5 and 3 unrated. Tornadoes before 2007 carry the original Fujita rating.
Compared with Illinois
| Measure | Knox County | Illinois | US |
|---|---|---|---|
| Tornado events since 1950 | 31 | 3,647 | 81,281 |
| Per 100 square miles | 4.3 | 6.6 | 2.3 |
| Per 10,000 residents | 6.3 | 2.9 | 2.4 |
| Deaths recorded | 0 | 236 | 6,410 |
| Busiest month | June | April | May |
By year
Seasonality
0Feb
0Mar
4Apr
6May
6Jun
10Jul
3Aug
1Sep
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 |
|---|---|---|---|---|---|---|---|
| 10 Mar 2026 | Tornado | EF1 | — | — | — | — | County |
| 20 Apr 2025 | Tornado | EF1 | — | — | — | — | County |
| 20 Apr 2025 | Tornado | EF1 | — | — | — | — | County |
| 15 Jul 2024 | Tornado | EF1 | — | — | — | — | County |
| 18 Jun 2021 | Tornado | EF1 | $150K | $100K | — | — | County |
| 28 Mar 2020 | Tornado | EF unrated | — | — | — | — | County |
| 27 May 2019 | Tornado | EF0 | — | — | — | — | County |
| 23 May 2017 | Tornado | EF0 | — | — | — | — | County |
| 5 Jun 2010 | Tornado | EF0 | — | $2K | — | — | County |
| 5 Jun 2010 | Tornado | EF2 | $420K | $50K | — | — | County |
| 8 Jun 2005 | Tornado | F0 | — | — | — | — | County |
| 20 Apr 2004 | Tornado | F0 | — | — | — | — | County |
| 30 Apr 2003 | Tornado | F0 | — | — | — | — | County |
| 11 Sep 2000 | Tornado | F0 | — | — | — | — | County |
| 22 Apr 1999 | Tornado | F0 | — | — | — | — | County |
| 29 Jun 1998 | Tornado | F1 | $2.0M | — | — | 1 | County |
| 3 Aug 1997 | Tornado | F0 | — | — | — | — | County |
| 18 May 1997 | Tornado | F0 | — | — | — | — | County |
| 30 Apr 1997 | Tornado | F0 | — | — | — | — | County |
| 13 May 1995 | Tornado | F2 | $1.6M | — | — | 2 | County |
| 6 Jul 1987 | Tornado | F1 | $3K | — | — | — | County |
| 4 Mar 1976 | Tornado | F2 | $25K | — | — | — | County |
| 23 Mar 1975 | Tornado | F2 | $25K | — | — | 2 | County |
| 20 Jun 1974 | Tornado | F1 | — | — | — | — | County |
| 20 Jun 1974 | Tornado | F0 | — | — | — | — | County |
| 20 Jun 1974 | Tornado | — | — | — | — | — | County |
| 20 Jun 1974 | Tornado | — | $3K | — | — | — | County |
| 14 Jun 1974 | Tornado | F3 | — | — | — | 1 | County |
| 7 May 1967 | Tornado | F1 | $250K | — | — | — | County |
| 21 Jul 1961 | Tornado | F1 | $250K | — | — | — | County |
| 14 May 1961 | Tornado | F3 | $2.5M | — | — | 8 | County |
Questions and answers
How many tornado events has Knox 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 Knox County?
10 Mar 2026 (Tornado, EF1). Records reach NCEI about 120 days after the month ends.
What was the most damaging tornado event recorded in Knox County?
The tornado of 14 May 1961, with property damage estimated by NCEI at $2.5M.
How does Knox County compare with Illinois for tornado?
4.3 events per 100 square miles against 6.6 statewide; the county holds 31 of the state's 3,647 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.