Weather · head-to-head
IPMA vs RainViewer
IPMA's open-data service is a plain directory of continuously-refreshed static JSON files, not just a single forecast endpoint: it covers daily/hourly weather forecasts, real-time station observations, sea-area and district warnings for mainland Portugal, the Azores and Madeira, plus separate seismic and biology (pollen) datasets from the same institute. No registration is required, though IPMA asks heavy users to email its webmaster for usage statistics.
RainViewer aggregates and re-tiles third-party radar imagery from over 1,200 radar stations across 150+ countries, refreshed every 5 minutes, and exposes it as XYZ PNG tile pyramids plus a JSON timeline endpoint listing available past and short-term nowcast frames. Coverage isn't guaranteed to be permanent since individual source radar owners can request their feed be pulled, and the service is explicitly licensed for personal, educational, and small-scale community projects only.
| IPMA | RainViewer | |
|---|---|---|
| Authentication | None | None |
| Pricing | free | free |
| Formats | JSON | JSON, PNG |
| CORS | yes | yes |
| HTTPS | Yes | Yes |
RainViewer supports 2 response formats, while IPMA offers fewer — pick RainViewer for more integration flexibility.