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The EF scale

SCALES & INSTRUMENTSHow tornadoes are rated — by the damage they leave, from EF0 to EF5.

You can't put a weather station inside a tornado and expect it back. So tornadoes are rated after the fact, by the damage they leave behind — using the Enhanced Fujita scale, EF0 to EF5, named after Dr. Tetsuya "Ted" Fujita, who invented the original in 1971.

>Reading damage like a detective

Survey teams walk the track and read structures like instruments: a snapped billboard implies one wind speed, a roof peeled from a well-built house another, a house swept clean off its foundation another still. The "Enhanced" in the name (2007) is a library of 28 damage indicators — from softwood trees to shopping malls — each calibrated to the wind needed to break it.

EF0 (105–137 km/h) — broken branches, loose roof tiles.
EF1 (138–177 km/h) — roofs stripped, mobile homes overturned.
EF2 (178–217 km/h) — roofs gone, large trees snapped, cars lifted.
EF3 (218–266 km/h) — walls of sturdy houses collapse, trains tip.
EF4 (267–322 km/h) — well-built homes leveled.
EF5 (322+ km/h) — strong houses swept away entirely; pavement peeled.

>The shape of the statistics

Weak tornadoes vastly outnumber strong ones — roughly 8 in 10 are EF0–EF1, and EF5s are once-in-years events even in the US. Europe's tornadoes follow the same pyramid: mostly weak, with rare painful exceptions like the EF3 in Paderborn, Germany (2022) or the EF4 in Czechia (2021).

One honest caveat: the scale measures damage, not the tornado itself. A monster tornado that crosses only empty fields breaks nothing rateable — and gets a modest number. The atmosphere doesn't grade on effort.