About LazeCast: methodology and data sources
LazeCast is a free weather assistant for what to wear and what to pack — today, this week, or for a trip to any city — tuned to how warm or cold you run. 24 languages.
Updated: November 12, 2026
Who runs LazeCast
LazeCast is an independent project, developed since May 2026 and run by the operator of the LazeCast service. It is free to use and works without an account.
Where the data comes from
- Forecasts: Open-Meteo and MET Norway (the Norwegian Meteorological Institute). Their forecasts are combined into one; if one source is unavailable, the other is used.
- Month-by-month pages: climate normals for 2015–2024 from the ERA5 reanalysis (via the Open-Meteo archive).
- City search: the Open-Meteo geocoding service.
- Hosting: Cloudflare — pages and the API run at the network edge; forecasts are cached for about 15 minutes.
How the advice is calculated
A transparent rule engine, not a black box: fixed thresholds turn temperature, feels-like temperature, wind, chance of rain, UV and humidity into clothing layers — for example, a jacket up to about +14 °C and shorts from about +20 °C in calm, dry weather.
What to wear by temperature: °C and °F chart
Your comfort profile (whether you run cold or warm, umbrella preference, personal thresholds) and your feedback shift these thresholds for you. Children get separate, age-aware outfits.
This is general comfort guidance, not medical or safety advice. In severe weather, follow official warnings.
How often it is updated
Forecasts are refreshed continuously, and every city page shows how fresh its data is. Guides and climate pages change only when the rules or the data set change; each shows its date.
Privacy
No account is needed. Exact coordinates are not stored: your location is used approximately, only to fetch the forecast. Privacy policy
Contact
Questions, corrections or partnership enquiries: [email protected]