Heat & drought
Drink about 2 to 3 litres spread throughout the day, avoid the midday heat and move exertion to the cool morning hours. Darken your flat during the day and ventilate it at night. Never leave people or animals in the car and pay attention to vulnerable neighbours.
Heatwaves are Switzerland's deadliest natural hazard — unlike storms or floods, they act invisibly and over days. Mainly affected are the elderly, small children, the chronically ill and people who work outdoors. The body overheats, the circulatory system is overloaded.
The hot summer of 2003 caused around 1000 additional deaths in Switzerland, the summer of 2022 around 623 — figures that far exceed those of storms and floods. With climate change, the frequency and intensity of heatwaves are increasing measurably.
Persistent drought additionally aggravates the risk of forest fires and can lead to water shortages. The protective measures are simple but effective: drink, cool down, avoid the midday heat — and look out for vulnerable neighbours.
Risk rating
Likelihood: High · Impact: Medium → Overall risk: High.
| Impact | |||
|---|---|---|---|
| Low | Medium | High | |
| High | This hazard's rating | ||
| Medium | |||
| Low | |||
Legend: Low (green) · Medium (yellow) · High (red). Overall risk is likelihood multiplied by impact.
Heatwaves strain the circulatory system and infrastructure; drought aggravates water shortages and the risk of forest fires.
Immediate measures
- Drink plenty, avoid the midday heat
- Cool and darken the home early
- Strictly observe fire bans
Warning signs
- MeteoSwiss heat warning level 3 or higher (thresholds based among other things on a high daily mean temperature over several days)
- Several consecutive tropical nights (the temperature does not drop below ~20 °C at night — the home no longer cools down)
- Early bodily signals: headache, dizziness, muscle cramps, dark urine (signs of dehydration/heat strain)
- Increased forest-fire danger level (waldbrandgefahr.ch), often accompanied by fire bans
- Official appeals to save water during persistent drought
Before · During · After
Before
- Subscribe to heat warnings from MeteoSwiss
- Ventilate the home at night and early in the morning
- Look out for vulnerable neighbours
During
- Drink 2–3 litres, avoid alcohol
- Schedule exertion for the morning hours
- Darken the home during the day, keep the heat outside
- Never leave people or animals in the car
After
- Keep observing fire bans – the ground stays dry
- Follow the municipality's water-saving orders
This really happened
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2023 Late heatwave
In August 2023 Switzerland experienced an exceptionally long, intense heatwave; around 20 measuring stations set new August records, with 39.3 °C in Geneva. It was the third-warmest summer since records began in 1864.
Source -
2022 Hot summer
The second-warmest summer after 2003 caused around 623 heat-related deaths; about 90 % of the victims were over 65 years old, and a study by the University of Bern attributed around 60 % to climate change.
Source -
2018 Drought summer
The summer half-year of 2018 was then the warmest since records began in 1864; on average only about half the usual precipitation fell, leading to increased forest-fire risk and water shortages.
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2015 Hot summer
The second-warmest summer of the measuring record at the time was around 2.4 °C above the norm; heat-related excess mortality was about 5.4 %, equivalent to around 800 additional deaths.
Source -
2003 Hot summer
The hottest summer since records began caused around 1000 additional deaths in Switzerland; for the first time, over 40 °C were measured.
Source
Frequently asked questions
How do I prepare for a heatwave?
Subscribe to heat warnings from MeteoSwiss. Ventilate your flat at night and early in the morning and keep it dark during the day. Pay special attention to vulnerable neighbours such as elderly or ill people.
How do I recognise the onset of heat stress?
Early body signals are headache, dizziness, muscle cramps and dark urine as a sign of dehydration. Multiple tropical nights in a row, where the temperature does not drop below about 20 °C and your flat no longer cools down, are also warning signs.
Why is heat so dangerous in Switzerland?
Heatwaves are Switzerland's deadliest natural hazard; they act invisibly over days. Particularly affected are elderly people, small children and the chronically ill. The hot summer of 2003 caused around 1000 additional deaths in Switzerland.
Official sources
- MeteoSwiss Heat warnings
- FOPH Health in hot weather
- Forest fire danger Current levels