
European · ECMWF IFS
European Centre for Medium-Range Weather Forecasts · EU (Reading, UK) · ~25 km (open 0.25° release)
Widely regarded as the world's most accurate global model. Run by a 35-nation European agency, its high-resolution forecast is the benchmark others are measured against.
Apps that ride on it: Apple Weather (in part), Windy

American · NOAA GFS
US National Oceanic and Atmospheric Administration · United States · ~13–25 km
The United States' flagship global model, fully open and updated four times a day. It powers a huge share of the free weather apps and tools on the internet.
Apps that ride on it: Many free apps, Windy
GeGerman · DWD ICON
Deutscher Wetterdienst · Germany · ~13 km global / 2 km regional
Germany's national model, known for sharp handling of European and mid-latitude weather. Open data, and a favourite third option on power-user tools.
Apps that ride on it: Windy

Met Office · UKMO Unified Model
UK Met Office · United Kingdom · ~10 km global
Britain's own national model, run by the Met Office. Strong over the UK and North Atlantic, and the model BBC Weather is returning to.
Apps that ride on it: Met Office app, BBC (returning)
EnEnv. Canada · ECCC GEM
Environment and Climate Change Canada · Canada · ~15 km global
Canada's national model, built for a country of extreme cold snaps and fast-moving systems. Published as open data by Environment Canada.
Apps that ride on it: underlies Canadian services

NWS · NWS National Blend of Models
US National Weather Service · United States · ~2.5 km
The official US statistical blend that fuses many models into one gridded forecast. It is what weather.gov and, in the US, Apple Weather lean on.
Apps that ride on it: Apple Weather (US), weather.gov
Common questions
What is a weather model?
A weather model is a physics simulation of the atmosphere run on a supercomputer. It takes the current state of the atmosphere and steps it forward in time. Every forecast you have ever seen — in any app — comes out of one of a handful of these models. The apps mostly just restyle the output.
Which weather model is the most accurate?
Over the long run the European model (ECMWF) is generally the strongest global model, and it tops our tested scoreboards in several markets. But no model wins every day or every place, which is exactly why we grade them per country and show all of them side by side rather than trusting one.
What is the difference between the ECMWF, GFS and ICON models?
ECMWF is the European model, GFS is the American model (NOAA), and ICON is the German model (DWD). They solve the same physics with different code, resolution and starting data, so they disagree — and that disagreement is the honest signal of how uncertain a forecast really is.
Do weather apps make their own forecasts?
Almost none do. Apple Weather, AccuWeather, The Weather Channel and BBC Weather blend these same public models and present one number. The value they add is design and features, not a separate forecast — so 'which app is most accurate' really comes down to which model verifies best where you are.