Hail: National Platform for Natural Hazards

Hail hazard map (by hailstone size, 20 years)

Switzerland is one of the most hail-prone countries in Europe. Hailstorms cause damage totalling tens of millions of Swiss francs almost every year.

Hailstorms are smaller than winter storms, usually a few kilometres long and less than a kilometre wide. They normally bring small hailstones (1-2 cm) with them. Larger or more intense events are either longer and/or have larger hailstones (3 cm, rarely 5 cm and larger). The hail hazard is not the same throughout the country, as the hazard map shows.

People and larger animals are only at risk from larger hailstones (5 cm or more). However, hail can cause major damage to buildings, cars and agricultural crops. In 2021, the cantonal buildings insurance companies paid out almost CHF 800 million for hail damage to buildings.

Hail insurance

Insurance companies lead the way

Cantonal building insurance companies have been insuring buildings against fire and natural hazards since the beginning of the 19th century. Shortly afterwards, private insurance companies were added, offering transport, household contents and motor vehicle insurance in addition to buildings insurance. Hail insurance for agricultural crops has also existed in Switzerland since 1880.

After a sharp increase in hail damage to flat roof membranes in the 1970s, the various players reacted: the cantonal building insurers (VKF), private insurers, manufacturing companies, the Swiss Society of Engineers and Architects (SIA) and the Swiss Federal Laboratories for Materials Testing and Research (EMPA) defined requirements for the materials, integrated these into the predecessor standard to the SIA 271 building standard and developed a hail test for this purpose. Today, various hail-tested components can be found in the hail register.

The accumulation of major damage events in 2019 led the Federal Office for Civil Protection (FOCP) to include hailstorms in the list of hazard scenarios in the risk analysis.

Hail damage increased significantly from the 1990s onwards.

National risk analysis «Disasters and emergencies in Switzerland»

List of hazard scenarios - Hailstorms (PDF)

Simulation of storms

Simulation of hailstorms

As part of an ETH project, a model chain is being developed that simulates and predicts hailstorms and estimates the associated damage to buildings, vehicles and agriculture. The simulations include today's climate and a warmer climate in the future.

scClim-Project of the ETH

Effective measures

Building owners, homeowners, tenants, farmers and car owners can protect themselves against hail damage. Examples of measures include

Technical measures

Construct buildings in accordance with SIA standards (e.g. SIA 261/1)
Protect sensitive and exposed components - such as plastic skylights or slatted blinds - with grilles, protective glass or canopies
Install hail protection nets over car parks
Protect agricultural crops with nets

Biological measures

Plant crops that are less susceptible to hail

Organisational measures

Pull up the blinds (modern glass windows are more resistant to hail than blinds)
Store cars

Automatic raising of the blinds

An intelligent system protects the blinds: as soon as a hail warning is received for the building, the blinds are raised automatically. If the risk of hail falls below a threshold value, the system gives the all-clear and lowers the blinds again.

Protection against natural hazards, hail protection simply automatic

Chronicle

Devastating hailstorms

1927

1927 was a black year for agricultural hail insurance: the company, which was not yet reinsured, had to make indemnity payments totalling CHF 6.7 million on premium income of CHF 3.3 million.

1994

1994 was a record year for hail statistics: on 10 August, a hailstorm hit the Haute-Borne region of the Jura in particular. Hailstones the size of tennis balls fell in Bassecourt and Pleigne near Delsberg.

Zürch, Turnerstrasse, Autofahren bei Regen und Hagel

2009

The hail fronts of 26 May and 23 July left a trail of devastation in their wake. Hailstones up to the size of tennis balls (> 5 cm) fell in French-speaking Switzerland, along with strong winds and heavy rain. Insurance companies paid out CHF 380 million in damages to vehicles, more than CHF 300 million to buildings and around CHF 10 million to agriculture.

IRV, Hail event analysis 2009 (pdf)

2011

On 12/13 July, a hailstorm hit Zofingen (AG) and parts of the canton of Zurich around midnight with hailstones that were sometimes the size of tennis balls. According to an analysis, the event was one of the strongest hailstorms ever recorded in the canton of Aargau. The insured damage to buildings alone totalled around CHF 200 million (CHF 150 million of which was in the canton of AG).

IRV, Hail event analysis 2011 (pdf)

Car roof damaged by major hailstorm hailstones. Car insurance repair dents. Dented car rooftop

2021

On 28 June, there was an extreme hailstorm in the region of Wolhusen (LU) with hailstones up to 9 cm in size. Roofs and photovoltaic systems were destroyed over large areas in many cases. The subsequent rainfall made some of the buildings uninhabitable. In total, damage to buildings, cars and agriculture totalled over CHF 600 million.