Duncan, OK Tornado History — 135 Tornadoes Since 1950
How many tornadoes has Duncan, OK had?
Duncan has had 135 tornadoes on record within 25 miles since 1950, including 13 violent (EF3+) tornadoes.
When was the most recent tornado near Duncan?
The most recent tornado within 25 miles of Duncan was an EF3 on November 3, 2024.
When is tornado season in Duncan?
May is historically the peak month for tornadoes near Duncan, with 45 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 Duncan
The last 20 years of confirmed tornadoes within 25 miles — 33 total, averaging 1.6 per year over this window.
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 Duncan
52 fatalities have been recorded within 25 miles of Duncan since 1950, across 5 events. 1,891 injuries have been reported across all events. 1979 was the deadliest year on record.
The deadliest single event was a F4 on April 10, 1979, which caused 42 fatalities along a 46.9-mile track.
Notable Tornadoes Near Duncan
About Tornadoes in Duncan
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 Duncan, Oklahoma 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 spring, when the contrast between retreating winter air and advancing warmth is sharpest. The underlying setup is a familiar one: Gulf moisture, dry air spilling off the higher terrain to the west, and a strong upper-level jet converge over the Plains. The resulting supercells are often discrete and visible for long distances, though that visibility should never be relied on as a substitute for a warning.
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 Duncan 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.