Norwegian hydrological API (HydAPI)
The Norwegian national hydrological record — discharge, water level, temperature and snow — served through NVE’s HydAPI at instantaneous, hourly and daily resolution, covering a dense gauging network across a country whose hydrology is dominated by snowmelt and hydropower regulation.
Rights
- Commercial reuse
- Yes
- Redistribution
- Yes
- Derivative use
- Yes
- Attribution required
- YesContains data from the Norwegian Water Resources and Energy Directorate (NVE), licensed under the Norwegian Licence for Open Government Data (NLOD).
- Terms last checked
- 26 August 2026
Access and coverage
- Publisher
- Norges vassdrags- og energidirektorat
- Geographic coverage
- Norway — national hydrological network
- Resolution
- Instantaneous, hourly and daily
- Update frequency
- real-time
- Formats
- json, api
- Bulk download
- Available
- Registration required
- Yes
- Rate limit
- Throttled per API key; each response returns x-rate-limit-limit, x-rate-limit-remaining and x-rate-limit-reset. Station and series metadata update about every four hours, and NVE asks clients to poll no more often than that and to cache large queries.
- Cost to Hydrionis
- Free
- Domains
- river flow, temperature, snow ice
Notes
Re-assessed on 26 August 2026 for Sprint 7 §12, and the rights position corrected. Sprint 6 recorded this as CC BY with commercial reuse unclear; it is in fact the Norwegian Licence for Open Government Data, which NVE states in its own API documentation and which is among the most permissive licences in this registry — the licensee "may use the information for any purpose and in all contexts", with attribution the only condition, and NVE confirms compatibility with CC BY 3.0 Norway. Automated ingestion is contemplated rather than merely tolerated: NVE publishes throttling headers, a changelog and guidance on efficient querying. The only barrier is the key, which is an access condition and not a rights restriction. A key-free Norwegian alternative was looked for and not found — the other NVE hydrology endpoints tried returned 404, and HydAPI itself returns 401. So Norway is not blocked in the sense GKD Bayern and OPW Hydro-Data are, where the terms do not permit the use; it is waiting for an authorisation only the user can give.