FAQ

The whole world. Europe — from Iceland and Scandinavia to Turkey and Cyprus, Italy included — gets the high-resolution national models, rain probability and the reliability index; everywhere else the forecast comes from global models. Zoom out from any point and the map keeps going; click anywhere and the location card opens.

Up to 4 days. City icons, the location card and the meteogram go hour by hour; the colour layers on the map are computed every 3 hours and blended smoothly in between.

The map is rebuilt every 3 hours and each source is refreshed as soon as new data is published. Location cards are computed live when you open them, so they always use the freshest data.

Italy and Europe, the United States, Canada and Taiwan. Over Italy the radar data comes from the Italian Civil Protection Department; over the rest of Europe from the EUMETNET/OPERA network; elsewhere from the national weather services (NOAA, Environment Canada, CWA). Where a country does not share radar data the map has no radar, but satellite imagery is available worldwide. Tap a point on an echo and you also get its intensity in dBZ — below 20 is a weak echo, above 45 very heavy precipitation. Remember it is an observation, not a forecast. More about the radar.

Wind (also aloft), snow, visibility, Air (PM2.5, PM10, ozone, nitrogen dioxide) and Sea (wave height, period and direction) worldwide, and Pollen across Europe (an overall level plus alder, birch, grass, mugwort, olive and ragweed one by one). Pollen comes from CAMS Europe, air from CAMS Europe and CAMS Global, waves from DWD EWAM and GWAM — modelled values, not station readings. See how they work.

ExtremeCast doesn't relay a single model: it compares several and produces its own reading, picking for each European area the best high-resolution source available — down to 1 km where national weather services publish it, so mountains and coastlines keep their detail instead of being flattened into a continental average. Outside Europe the forecast comes from global models.

There's processing. Several sources are compared and merged into one consistent reading, the values are corrected to the real altitude of your location, and, in Europe, two numbers are computed by us: the rain probability and the reliability index. What you read is ExtremeCast's own elaboration, not a relayed feed.

From several independent models plus the behaviour of the surrounding area on our high-resolution grid. Rain is local — what the number really tells you is how likely a shower is around you, which is the honest question.

How much the models agree at your spot. High = solid; low = the atmosphere is uncertain there, check again later. We prefer showing uncertainty over hiding it.

Open-Meteo and the national weather services (DWD, Météo-France, MeteoSwiss, GeoSphere, KNMI, DMI, MET Norway, CHMI, UK Met Office, ARPAE), under CC-BY licence. Model selection, rain probability and the reliability index are ExtremeCast processing. Observed radar comes from the Italian Civil Protection Department over Italy, the EUMETNET/OPERA network over the rest of Europe, NOAA MRMS in the United States, Environment and Climate Change Canada and Taiwan's Central Weather Administration. Satellite imagery: EUMETSAT, NOAA GOES and JMA Himawari. Pollen comes from CAMS Europe and air quality from CAMS Europe and CAMS Global (Copernicus); waves from the DWD EWAM and GWAM models.

Because it isn't a model output: it is our own machine-learning engine, re-trained every night and scored against Italian radar, 3,750+ ground stations and human storm reports. Every colour on that map is calibrated against what actually happened. Extending it to another country means rebuilding that ground-truth chain there first — we'd rather do it properly than paint colours we cannot verify.

It maps hail, damaging wind gusts, torrential rain and storm cells zone by zone up to 48 hours ahead, with time windows, observed radar and e-mail alerts. Its pages and interface are in Italian: read more (Italian).

Weather at the real altitude of 46,000 Italian peaks, huts, passes and trails: snow line, ridge wind, cloud base, trail-by-trail forecasts on your GPX, plus a winter mode with ski slopes and snow bulletins. Italian Alps and Apennines only, interface in Italian: read more (Italian).

Possibly. The honest requirement is open radar plus reliable ground reports for the target country, and then months of verification before we'd show a single colour. Germany is the natural first candidate. No promises on dates.

The weather map is free worldwide and needs no account. A subscription covers the Italian severe-risk product, e-mail alerts, storm nowcasting and the advanced mountain tools.

Yes — it's a progressive web app. From your browser, add it to the home screen: it opens full screen like a native app, on phone and desktop, with no app store involved.

The map interface is available in Italian, English, French, German and Spanish (it follows your browser language, and you can switch it manually at any time).

No. ExtremeCast is an informational and experimental tool. For warnings and safety decisions always refer to your national weather service and civil protection authority.