1974 Super Outbreak
The 1974 Super Outbreak was the second-largest tornado outbreak on record for a single 24-hour period, just behind the 2011 Super Outbreak. It was also the most violent tornado outbreak ever recorded, with 30 F4/F5 tornadoes confirmed. From April 3–4, 1974, there were 148 tornadoes confirmed in 13 U.S. states and the Canadian province of Ontario. In the United States, tornadoes struck Illinois, Indiana, Michigan, Ohio, Kentucky, Tennessee, Alabama, Mississippi, Georgia, North Carolina, Virginia, West Virginia, and New York. The outbreak caused roughly $843 million USD (equivalent to $5.21 billion in 2023) in damage, with more than $600 million (equivalent to $3.71 billion in 2023) occurring in the United States. The outbreak extensively damaged approximately 900 sq mi (2,331 km2) along a total combined path length of 2,600 mi (4,184 km). At one point, as many as 15 separate tornadoes were occurring simultaneously.
Paths of the 148 tornadoes generated in United States during the 1974 Super Outbreak. One tornado was deconfirmed and determined to be a microburst. | |
| Meteorological history | |
|---|---|
| Duration | April 3–4, 1974 |
| Tornado outbreak | |
| Tornadoes | 148 |
| Maximum rating | F5 tornado |
| Overall effects | |
| Fatalities | 335 fatalities |
| Damage | $843 million (1974 USD) $5.30 billion (2024 USD) |
| Areas affected | Midwestern and Southern United States, Ontario, Canada |
Part of the tornado outbreaks of 1974 | |
The 1974 Super Outbreak was the first tornado outbreak in recorded history to produce more than 100 tornadoes in under a 24-hour period, a feat that was not repeated globally until the 1981 United Kingdom tornado outbreak and in the United States until the 2011 Super Outbreak. In 2023, tornado expert Thomas P. Grazulis created the Outbreak Intensity Score (OIS) as a way to rank various tornado outbreaks. The 1974 Super Outbreak received an OIS of 578, making it the worst and most violent tornado outbreak in recorded history.