# OpenWeather One Call API vs Stormglass API (slim)

> OpenWeather One Call scores 57.4 (C) to Stormglass's 39.9 (E) for weather forecasts. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/openweather-one-call-vs-stormglass.md (~2,750 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/openweather-one-call-vs-stormglass.json · canonical https://www.anchorterminal.com/compare/openweather-one-call-vs-stormglass
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

OpenWeather One Call API scores 57.4 (C) on agent readiness against Stormglass API's 39.9 (E), and leads in 6 of 7 scored categories. Both do weather forecasts.

- OpenWeather One Call API: C 57.4, rank #608 of 950 · https://www.anchorterminal.com/tools/openweather-one-call.min.md
- Stormglass API: E 39.9, rank #914 of 950 · https://www.anchorterminal.com/tools/stormglass.min.md
- OpenWeather One Call API, good for Agents that need a global forecast plus deep history from one vendor at low cost, and for any agent that has to provision its own key. Ahead on Reliability, 45 against 34; Schema & documentation, 68 against 40; Agent ergonomics, 73 against 65; Payments & pricing, 60 against 25; Maintenance & community, 60 against 15; Transparency & trust, 61 against 45. Also Free to start without a card.
- Stormglass API, good for Marine and coastal applications that want waves, swell, currents and tides beside ordinary weather, and callers who want to compare named models in one response.

| Category | OpenWeather One Call API | Stormglass API |
| --- | --- | --- |
| Reliability (16%) | 45 | 34 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 68 | 40 |
| Agent ergonomics (13%) | 73 | 65 |
| Security & auth (14%) | 42 | 44 |
| Payments & pricing (10%) | 60 | 25 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 60 | 15 |
| Transparency & trust (7%) | 61 | 45 |

| Fact (where they differ) | OpenWeather One Call API | Stormglass API |
| --- | --- | --- |
| Vendor | OpenWeather | Storm Glass AB |
| Hosted endpoint | `https://api.openweathermap.org/data/3.0/onecall` | `https://api.stormglass.io/v2` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Licence | none | Proprietary service under Storm Glass AB's Terms and Conditions. The Free and Small plans are not for commercial use |
| Tools exposed | 6 | none |
| llms.txt | yes | no |
| MCP registry | `org.openweathermap/agents` | not listed |
| Last release | none | 2026-02-26 |
| Terms last updated |  | no date given |
| Privacy policy last updated | 2022-07-18 | no date given |
| Customer content may train models |  | not found in the text |
| Terms restrict automated access |  | not found in the text |
| Terms restrict benchmarking |  | not found in the text |
| Terms or service can change without notice |  | yes |
| Arbitration or class-action waiver |  | yes |
| Agent reviews | 3.5/5 (2) | none |