# Stormglass API vs Tomorrow.io Weather API (slim)

> Tomorrow.io Weather scores 51.4 (D) 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/stormglass-vs-tomorrow-io.md (~2,900 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/stormglass-vs-tomorrow-io.json · canonical https://www.anchorterminal.com/compare/stormglass-vs-tomorrow-io
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

Tomorrow.io Weather API scores 51.4 (D) on agent readiness against Stormglass API's 39.9 (E), and leads in 5 of 7 scored categories. Stormglass API leads on security & auth and payments & pricing. Both do weather forecasts.

- Stormglass API: E 39.9, rank #914 of 950 · https://www.anchorterminal.com/tools/stormglass.min.md
- Tomorrow.io Weather API: D 51.4, rank #751 of 950 · https://www.anchorterminal.com/tools/tomorrow-io.min.md
- 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. Ahead on Security & auth, 44 against 34; Payments & pricing, 25 against 20.
- Tomorrow.io Weather API, good for Teams that need minute-level and route or polygon forecasts, alert webhooks and a hosted MCP server, and will buy through sales. Ahead on Reliability, 55 against 34; Schema & documentation, 75 against 40; Agent ergonomics, 73 against 65; Maintenance & community, 27 against 15; Transparency & trust, 63 against 45.

| Category | Stormglass API | Tomorrow.io Weather API |
| --- | --- | --- |
| Reliability (16%) | 34 | 55 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 40 | 75 |
| Agent ergonomics (13%) | 65 | 73 |
| Security & auth (14%) | 44 | 34 |
| Payments & pricing (10%) | 25 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 15 | 27 |
| Transparency & trust (7%) | 45 | 63 |

| Fact (where they differ) | Stormglass API | Tomorrow.io Weather API |
| --- | --- | --- |
| Vendor | Storm Glass AB | The Tomorrow Companies Inc. |
| Hosted endpoint | `https://api.stormglass.io/v2` | `https://api.tomorrow.io/v4` |
| Auth | API key | OAuth or key |
| Licence | Proprietary service under Storm Glass AB's Terms and Conditions. The Free and Small plans are not for commercial use | Proprietary service under Tomorrow.io's subscription terms |
| Tools exposed | none | 11 |
| llms.txt | no | yes |
| Last release | 2026-02-26 | 2026-07-14 |
| Terms last updated | no date given | couldn't be read |
| Privacy policy last updated | no date given | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | not found in the text | couldn't be read |
| Terms or service can change without notice | yes | couldn't be read |
| Arbitration or class-action waiver | yes | couldn't be read |