Mason City, IA Tornado History — 114 Tornadoes Since 1950
How many tornadoes has Mason City, IA had?
Mason City has had 114 tornadoes on record within 25 miles since 1950, including 12 strong to violent (EF3+) tornadoes.
When was the most recent tornado near Mason City?
The most recent tornado within 25 miles of Mason City was an EF0 on July 28, 2025.
When is tornado season in Mason City?
June is historically the peak month for tornadoes near Mason City, with 28 on record. April through June account for 54 of the 114 tornadoes on record near Mason City.
At a Glance
Recent Tornado Activity Near Mason City
The last 20 years of confirmed tornadoes within 25 miles — 37 total, averaging 1.9 per year over this window.
Preliminary tornado reports near Mason City since December 29, 2025
These are 3 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Preliminary reports are revised, merged, and sometimes withdrawn — historically about 23% are consolidated downward once surveys complete.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.
Cerro Gordo County Dispatch relayed via radio that a tornado had touched down east of Swaledale. (DMX)
Local fire reports tornado on ground. (DMX)
Structure damage. Time estimated via radar. (DMX)
Within 25 miles of Mason City. Quoted text is the report narrative exactly as filed. 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 Mason City
20 fatalities have been recorded within 25 miles of Mason City since 1950, across 3 events. 655 injuries have been reported across all events. 1968 was the deadliest year on record near Mason City.
The deadliest single event was an F5 on May 15, 1968, which caused 13 fatalities along a 62.1-mile track.
Notable Tornadoes Near Mason City
What the record shows near Mason City
The 2020s are the busiest decade on record so far near Mason City, with 23 of the 114 confirmed tornadoes within 25 miles. The Mason City record runs from the 1950s to today.
Of the tornadoes rated near Mason City, 80 reached EF0 or EF1 and 30 reached EF2 or stronger. The most intense on record near Mason City is rated EF5, of which 2 are logged. A further 4 near Mason City are unrated — events NOAA logged before a damage survey assigned a scale.
Across the last 20 years Mason City has averaged 1.9 confirmed tornadoes a year within 25 miles, 37 in total. 2021 was the busiest of them with 16, and 9 of those years passed with none at all.