Ottawa, IL Tornado History — 105 Tornadoes Since 1950
How many tornadoes has Ottawa, IL had?
Ottawa has had 105 tornadoes on record within 25 miles since 1950, including 8 violent (EF3+) tornadoes.
When was the most recent tornado near Ottawa?
The most recent tornado within 25 miles of Ottawa was an Unrated on July 14, 2024.
When is tornado season in Ottawa?
June is historically the peak month for tornadoes near Ottawa, with 40 on record. Spring through early summer (April–June) generally sees the highest activity across most of the central and southern United States.
At a Glance
Recent Tornado Activity Near Ottawa
The last 20 years of confirmed tornadoes within 25 miles — 55 total, averaging 2.8 per year over this window.
Preliminary tornado reports near Ottawa since December 29, 2025
These are 4 preliminary reports, not confirmed tornadoes. They have not yet been through an NWS damage survey, and are not counted in the confirmed totals above.
Preliminary reports are revised, merged, and sometimes withdrawn — historically about 23% are consolidated downward once surveys complete. Ratings are omitted until a survey assigns one.
Confirmed records above are complete through December 29, 2025. NOAA publishes the confirmed archive annually, so tornadoes after that date appear here first and move into the totals above once finalized.
Within 25 miles of Ottawa. Source: NOAA Storm Prediction Center preliminary storm reports, updated daily.
Tornadoes by Decade
Tornadoes by Enhanced Fujita Rating
F0–F5 ratings (pre-2007) are grouped with their EF equivalents. The Enhanced Fujita scale replaced the original Fujita scale in February 2007.
Tornadoes by Month
Casualties on Record Near Ottawa
17 fatalities have been recorded within 25 miles of Ottawa since 1950, across 6 events. 286 injuries have been reported across all events. 2004 was the deadliest year on record.
The deadliest single event was a F3 on April 20, 2004, which caused 8 fatalities along a 15.8-mile track.
Notable Tornadoes Near Ottawa
About Tornadoes in Ottawa
This overview was written July 27, 2026. The tornado counts and notable-event figures elsewhere on this page reflect the latest data and may differ from this summary.
The Ottawa, Illinois area sits within a part of the country where tornadoes are a recurring part of the climate rather than a rare anomaly. The tornado history summarized on this page is drawn from the NOAA Storm Prediction Center's severe weather database, which covers the area within the search radius shown above. The counts, ratings and individual events listed on this page are generated directly from that database and update as it is revised, so they always reflect the current record rather than a snapshot frozen at the time this summary was written.
Activity in this area concentrates most heavily in the summer months, when daytime heating does most of the work. The underlying setup is a familiar one: Gulf moisture pushes north into the Corn Belt ahead of strong low-pressure systems and their trailing cold fronts. Activity here frequently arrives as fast-moving squall lines as well as discrete supercells, and both can produce tornadoes.
Tornado intensity is described using the Enhanced Fujita scale, which runs from EF0 for the weakest tornadoes to EF5 for the most extreme, and which rates a tornado by the damage it leaves behind rather than by wind speed measured directly. Most tornadoes in the area have been at the weaker end of the scale, but the record also includes violent tornadoes at the top of it. That matters more than the raw frequency does: a single violent tornado can cause more damage and loss than decades of weaker events combined. Tornadoes in this area have caused loss of life; the casualty figures and the specific events behind them are listed above, straight from the record.
One caveat is worth carrying into any look at the numbers above: the modern record begins in 1950, and reported tornado counts have risen over the decades in large part because detection and reporting have improved. Doppler radar, storm spotter networks, mobile phones and denser development all mean that tornadoes which would once have gone unrecorded are now documented. A rising count does not by itself prove that more tornadoes are forming. The practical takeaway for Ottawa residents is unchanged: know where your safe room is, keep a way to receive warnings that will wake you at night, and treat every warning as though it applies to you, because the record here shows that it can.