Pas-de-Calais

Recorded Natural Hazards (Géorisques)

It has 887 municipalities and 1,457,905 inhabitants. Under the seismic zoning in force since 2011, its highest seismicity is moderate (zone 3 of 5). A natural disaster has been declared 5,744 times since 1982 (one declaration per municipality and decree), mostly for floods (4,250) and ground movements (1,081). The most recent was signed on 18 January 2026. 7 municipalities have a high radon potential (category 3), home to 0% of inhabitants. 272 municipalities are covered by an approved natural hazard prevention plan.

Seismicity Zones

Number of municipalities in each zone of the regulatory seismic zoning (from 1, very low, to 5, high).

Natural Disasters Declared Since 1982

Declarations per five-year period.

Most Widespread Events

• 1999Ground Movements · 25 December 1999890 municipalities
• 1999Floods and Mudflows · 25 December 1999890 municipalities
• 2023Floods and Mudflows · 13 November 2023263 municipalities
• 2023Floods and Mudflows · 2 November 2023181 municipalities
• 1993Floods and Mudflows · 19 December 1993180 municipalities
• 2023Floods and Mudflows · 27 December 2023153 municipalities

Most Frequently Affected Municipalities

• 25Boulogne-sur-Mer
• 22Clairmarais
• 21Aire-sur-la-Lys
• 21Neufchâtel-Hardelot
• 21Saint-Étienne-au-Mont
• 21Zutkerque
• 20Saint-Omer
• 20Wimereux

Hazards Listed by Municipality

Number of municipalities exposed to each natural hazard according to the departmental major risks file.

Hazards at a specific address on Géorisques