The 2017 Poland Derecho
On the night of 11β12 August 2017, a violent derecho swept across northern Poland, killing several people and flattening tens of thousands of hectares of forest β one of the most destructive windstorms in the country's history.
At a glance
| Date | 11β12 August 2017 |
|---|---|
| Type | Derecho (long-lived windstorm) |
| Worst-hit region | Pomerania & Kuyavia (Bory Tucholskie) |
| Signature damage | Tens of thousands of hectares of forest destroyed |
What happened
A fast-moving line of severe thunderstorms β a derecho β raced across northern Poland overnight on 11β12 August 2017, producing widespread wind gusts strong enough to snap and uproot mature trees across huge areas. The storm killed several people, including two scouts at a camp, and injured many more.
A forest catastrophe
The derecho's most staggering impact was on Poland's forests. It levelled tens of thousands of hectares of woodland, especially in the Bory Tucholskie region β one of the largest single wind-damage events ever recorded in Polish forestry. Cleanup and replanting took years.
Derecho vs tornado
A derecho is not a tornado. Instead of a rotating column, it is a broad, fast-moving complex of thunderstorms that produces damaging straight-line winds over a long, wide swath. The damage can rival a tornado outbreak but is spread across a far larger area. Learn the difference in our derecho vs tornado explainer.
Sources & further reading
- IMGW-PIB reports on the August 2017 windstorm
- Polish State Forests (Lasy PaΕstwowe) damage assessments
- European Severe Storms Laboratory event reports
Figures such as casualties and ratings reflect widely published accounts from national weather services and the European Severe Storms Laboratory, and may be revised as records are re-analysed.