How weather forecasts work

Modern weather forecasts come from numerical weather models — large physics simulations of the atmosphere. The forecast you see for any city blends results from several models (ECMWF, GFS, DWD) interpolated to the exact coordinates.

Accuracy is highest in the next 6 to 24 hours, very good up to 5 days, and softer beyond that. By 14 days out the forecast is more of a climatology nudge than a precise prediction.

Updates land roughly every hour from Open-Meteo's open-data API.