| Formed: | 4 July 2023 |
| Dissipated: | 7 July 2023 |
| Lowest Pressure: | 987 |
| Gusts: | 150 km/h (90 mph) |
| Damages: | €50,000,000 (2023) |
| Fatalities: | 2 |
| Affected: |
|
| Season: | 2022–23 European windstorm season |
Storm Poly, also known as or Cyclone Poly,[1] was an extremely violent European windstorm which affected Benelux, Germany, and the United Kingdom during July 2023. The thirty-seventh windstorm of the 2022–23 European windstorm season, Poly was named by the Free University of Berlin on 4 July. It later became the most intense summer storm to impact the Netherlands, bringing destructive gusts to the nation, peaking at 92abbr=onNaNabbr=on in IJmuiden.[2] [3] In Germany, lesser winds of 50- were recorded.[4] In total, two fatalities occurred: one in the Netherlands, and another in Germany.[5] Poly caused at least (2023) in damages.[6] There was a mild storm surge in the Netherlands due to Poly, which caused limited floodings in combination with a large amount of precipitation.
The Netherlands was affected the most by the storm.[7] A red wind warning was issued for the provinces of North Holland, Flevoland and Friesland as strong gusts were expected.[8] In the Schiphol Airport in Amsterdam, around 400 flights were canceled.[9] Hundreds were stranded in Amsterdam's central station since several domestic and overseas rail services were cancelled.[10] Hurricane-force winds were measured in the province of Noord-Holland, causing large amounts of destruction. Poly was the first very severe storm in the Netherlands since the 18th of January 2018 and the strongest storm since 1990 in general. It was also the first very severe storm in the summer, obliterating all previous records. Poly was also responsible for local floodings in the Netherlands. [11] Over 25,000 people lost electricity due to hurricane Poly. [12]
The Deutscher Wetterdienst issued a level-three red warning for most of northern Germany, including Hamburg.[13] High-speed rail services to Cologne and Hamburg were cut off. Additionally, some ferries from Germany to islands off the north coast were canceled, while powerful gusts toppled trees, disrupting a line between Hamburg and Sylt.[14]
The precursor low-pressure area to Poly would produce heavy rain for East Anglia, causing a game in Wimbledon to be postponed.[15] In Belgium, the Royal Meteorological Institute issued a code-yellow alert for all of the Flemish provinces, excluding Flemish Brabant, on July 5.[16] When Poly affected Belgium, it primarily brought severe thunderstorms and locally intense gusts to the nation.[17]
| Country | Gust | Location | |
|---|---|---|---|
 Belgium | De Panne | ||
 Germany | Leuchtturm Alte Weser | ||
 Netherlands | IJmuiden | ||
 United Kingdom |