Frequently asked questions
What you need to know about our forecasts, our data and using the site.
Where does the weather data come from?
Forecasts come from Open-Meteo, which aggregates the ICON (German weather service) and IFS (European Centre for Medium-Range Weather Forecasts) numerical models at roughly 2 km resolution over the Alps. The climate normals shown per municipality are computed from official MeteoSwiss measurements (SwissMetNet network, 1991–2020). The precipitation radar is provided by RainViewer.
Why do some municipalities have no forecast?
Every Swiss municipality is covered: the model provides a value at each grid point, which we interpolate to the municipality's coordinates and altitude. If a page stays empty, it is a temporary API problem or a dropped connection — reload the page. The pre-rendered fallback forecast stays visible even without JavaScript.
How do I report an error in a forecast?
Use the "Report severe weather" button on any municipality page, or the contact form. Give the municipality, the date and the difference you observed. This feedback helps us spot cases where the altitude used or the reference station does not match the terrain, especially in narrow valleys.
How often is the data updated?
The forecasts on screen are fetched on each visit and cached for about fifteen minutes. The models themselves are re-run several times a day. The static seven-day summary on each page is regenerated every night, and radar images refresh roughly every ten minutes.
How does the air quality index work?
It follows the European scale and combines fine particles (PM2.5, PM10), nitrogen dioxide and ozone, based on analyses from the European CAMS service. In winter, inversions concentrate particles in the valleys; in summer, sunshine produces ozone, especially south of the Alps. From the "poor" level upwards, sensitive people should avoid intense outdoor exercise.
Is the service free?
Yes — free and with no sign-up, for all 2,200 municipalities as well as ski resorts, lakes, passes and visitor sites. The site is funded by advertising, which lets us keep the data open to everyone.
Can I use this data in my own app?
The raw data comes from Open-Meteo and MeteoSwiss: go to those sources directly, and their terms apply (Open-Meteo allows free non-commercial use with attribution). Our pages are not meant to be scraped. For a partnership or a widget on your site, get in touch.
Still stuck? Write to us through the contact form — we usually reply within 24 to 48 hours.