Lab - live map
Is flooding coming where you are?
A federal hazard map knows where water goes when a rare event happens. A forecast knows how rare the rain arriving this week is. Deluge multiplies the two and shows the answer for every 5 km² of Switzerland, hour by hour, for the next three days.
A model, not a warning
Deluge is built by NinoLabs and has no official status. Binding warnings for Switzerland are issued by MeteoSwiss and the Federal Office for the Environment, and they are drawn on this map as their own layer. Check them first at naturgefahren.ch.
The chance that flooding of any kind happens somewhere in a 5 km² area. The three beside it are the causes.
Tap anywhere on the map to see the number for that area and what drives it.
How to read it
An area, not an address
One coloured patch covers about 5 km². It says flooding is likely somewhere inside it, not that your street is the place.
Colour is likelihood only
How deep the water could get is written in the panel and never mixed into the colour, so two areas of the same colour can mean a wet cellar and a dangerous street.
One hour at a time
The map always shows a single forecast hour. The bar underneath shows how the danger moves through the next three days.
What it cannot see
Drainage networks are not published in Switzerland, so flooding from an overloaded drain is only represented indirectly, through the terrain.
The forecast is sampled every 12 km while a summer thunderstorm cell is 1 to 5 km across, so a convective core can fall between sample points and be underestimated.
There is no hydraulic river routing. River risk is local rainfall rarity plus the state of the nearest official gauge, not a discharge simulation.
The probability scale is physically reasoned but not verified against a damage database, because no such database is open in Switzerland.
River flooding is shown as whole 5 km cells: the federal flood-zone map behind it may not be republished at finer resolution, so this map deliberately does not.
Where the data comes from
Every number traces to an official Swiss source. Nothing here is crowdsourced, and where a source is missing the map says so rather than approximating it into existence.
Federal hazard maps
FOEN overland flow map, Aquaprotect flood extents and SilvaProtect landslide and debris-flow zones. They say where water goes. None of them is legally binding, and the cantonal hazard maps remain the reference document.
Forecast
MeteoSwiss ICON-CH1 and ICON-CH2 precipitation relayed by Open-Meteo, plus ECMWF soil moisture. Refreshed every four hours.
What has already fallen
MeteoSwiss station rainfall and the CombiPrecip radar composite, so hours that have already happened are driven by measurement rather than by the forecast.
Official warnings
FOEN flood warnings, gauge hazard levels and river state, passed through untouched. They act as a floor: Deluge never shows less danger than the official warning in force.
Sources: Federal Office for the Environment (FOEN), MeteoSwiss, Federal Office of Topography swisstopo, Open-Meteo (CC-BY 4.0). Federal geodata used under the terms of geo.admin.ch. Aquaprotect is used only as an aggregate per 5 km cell and is not republished as flood zones.
The method, in short
For each 5 km cell the model asks how rare the forecast rain is there, using rainfall statistics fitted to a century of MeteoSwiss station records rather than a national average.
That rarity is combined with how much of the cell the federal hazard maps mark as reachable by water, and with how wet the ground already is after what has measurably fallen in the past 72 hours.
Official FOEN warnings and gauge levels are then applied as a floor. The result is a probability per mechanism, an expected depth class and a confidence, and all three are shown rather than reduced to one number.
Legal note
Deluge is provided free and as is, without warranty of any kind. It establishes no legal claim, replaces no cantonal hazard map and no official warning, and must not be the only basis for a decision that protects people or property.
In an emergency call 112. Binding warnings are published by the FOEN and MeteoSwiss.