Data sources and methodology
Trustworthy weather coverage starts with being honest about where data comes from and what its limits are. This page explains what WeatherZ shows, how we present it, and the rules our AI assistant follows.
Forecast data
WeatherZ forecasts are generated from leading numerical weather-prediction models that are continuously updated with observational data. The platform automatically selects the best-performing model for each UK location and blends output where that improves accuracy. Location search and place-name resolution use standard geocoding services.
Limits: all model forecasts carry uncertainty that grows with lead time. Beyond about five days, treat any daily forecast as an indication of pattern, not a promise of detail. Where the platform shows risk indicators (for example thunderstorm potential), they are derived from model instability fields and are probabilistic by nature.
Rainfall radar
UK radar imagery on WeatherZ is sourced from national meteorological radar networks and displayed with the required attribution. Every frame is timestamped so you can always tell how recent the data is. Radar shows precipitation detected aloft, not guaranteed rain at the surface: see how rainfall radar works for the honest limitations.
Maps
Base maps are built on OpenStreetMap data, © OpenStreetMap contributors, displayed via a dark-themed tile service suited to the WeatherZ design.
The town and village names on the ChaserZ board come from GeoNames, used under the Creative Commons Attribution 4.0 licence.
Warnings and flood information
Official severe-weather warnings are issued by the Met Office; flood alerts and warnings by the Environment Agency, Natural Resources Wales, SEPA and DfI Rivers. WeatherZ summarises, maps and explains these - it does not issue them, and any WeatherZ summary always links back to the issuing authority. If our explanation and an official warning ever appear to disagree, the official warning wins.
Community reports
Reports, photos and videos are submitted by WeatherZ members and are clearly labelled as community observations - including their moderation state (for example verified or unverified). Locations are published at reduced precision to protect contributors' privacy. Reports are moderated and rate-limited; see how to report severe weather for the standards we hold reports to.
Zedbot and AI-generated content
Zedbot is WeatherZ's AI weather assistant. Its rules are fixed:
- Every AI-generated explanation is labelled as AI and shows when it was generated;
- It explains only the data on the page - it does not invent warnings, observations or precision the data doesn't contain;
- It distinguishes data ("radar shows heavy rain 20 miles west") from interpretation ("your area will likely see it within the hour");
- It never overrides official safety guidance, and safety-relevant content is reviewed and tightly constrained rather than free-form.
Display conventions
WeatherZ uses British conventions throughout: Celsius for temperature, millimetres for rainfall, miles per hour for wind, and UK time (GMT/BST) with 24-hour clock. Data timestamps show when the underlying source last updated, not just when the page loaded.
Corrections
If something on WeatherZ is wrong - a data error, a mislabelled report, a misleading explanation - tell us. Corrections are made promptly and materially significant ones are noted on the affected page.