# Tomorrow.io Weather API vs Weatherbit API

> Weatherbit API scores 57.7 (C) on agent readiness against Tomorrow.io Weather API's 51.4 (D), and leads in 3 of 7 scored categories. Tomorrow.io Weather API leads on agent ergonomics and maintenance & community. Both do weather current. Category scores, facts, verdicts and agent…

- Canonical: https://www.anchorterminal.com/compare/tomorrow-io-vs-weatherbit
- Markdown: https://www.anchorterminal.com/compare/tomorrow-io-vs-weatherbit.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/tomorrow-io-vs-weatherbit.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/tomorrow-io-vs-weatherbit.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Weatherbit API scores 57.7 (C) on agent readiness against Tomorrow.io Weather API's 51.4 (D), and leads in 3 of 7 scored categories. Tomorrow.io Weather API leads on agent ergonomics and maintenance & community. Both do weather current.

- Tomorrow.io Weather API: grade D, 51.4/100, rank #578 of 722. Markdown https://www.anchorterminal.com/tools/tomorrow-io.md · JSON https://www.anchorterminal.com/api/v1/tools/tomorrow-io.json
- Weatherbit API: grade C, 57.7/100, rank #466 of 722. Markdown https://www.anchorterminal.com/tools/weatherbit.md · JSON https://www.anchorterminal.com/api/v1/tools/weatherbit.json

## Which one, for what

### Tomorrow.io Weather API (D)

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:
- Agent ergonomics, 73 against 61
- Maintenance & community, 27 against 21

Watch for: No public price for paid use. The plan table lists Free and Enterprise, the second by quote

### Weatherbit API (C)

Good for: An application that needs forecasts plus specialised datasets (air quality, lightning, soil and degree days) from one paid subscription, queried by coordinates.

Ahead on:
- Reliability, 91 against 55
- Security & auth, 39 against 34
- Payments & pricing, 30 against 20

Also in its favour:
- Free to start without a card

Watch for: The key is accepted only as the `key` query parameter, and the spec lists plain http as a scheme


## Score by category

| Category | Weight | Tomorrow.io Weather API | Weatherbit API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 55 | 91 | Weatherbit API +36 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 72 | Tomorrow.io Weather API +3 |
| Agent ergonomics | 13% (16.2 this run) | 73 | 61 | Tomorrow.io Weather API +12 |
| Security & auth | 14% (17.5 this run) | 34 | 39 | Weatherbit API +5 |
| Payments & pricing | 10% (12.5 this run) | 20 | 30 | Weatherbit API +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 27 | 21 | Tomorrow.io Weather API +6 |
| Transparency & trust | 7% (8.8 this run) | 63 | 63 | even |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **51.4 · D** | **57.7 · C** | |

## Facts side by side

| Fact | Tomorrow.io Weather API | Weatherbit API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | The Tomorrow Companies Inc. | Weatherbit LLC |
| Hosted endpoint | `https://api.tomorrow.io/v4` | `https://api.weatherbit.io/v2.0` |
| Transports | HTTP | HTTP |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Proprietary service under Tomorrow.io's subscription terms | Proprietary service under Weatherbit's terms of service. The free plan's data is under a Creative Commons non-commercial licence. The Python SDK is MIT |
| Tools exposed | 11 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| Last release | 2026-07-14 | 2025-08-01 |
| Terms last updated | couldn't be read | 2025-05-01 |
| Privacy policy last updated | couldn't be read | 2023-12-26 |
| Customer content may train models | couldn't be read | not found in the text |
| Terms restrict automated access | couldn't be read | not found in the text |
| Terms restrict benchmarking | couldn't be read | not found in the text |
| Terms or service can change without notice | couldn't be read | not found in the text |
| Arbitration or class-action waiver | couldn't be read | not found in the text |
| Popularity | none | 78 PyPI/wk |

## Verdicts

**Tomorrow.io Weather API.** A public OpenAPI 3.1 file, Markdown docs with llms.txt and a hosted MCP server with 11 tools suit agents, and a free plan exists. Paid prices are by quote only, free keys are barred from commercial use, the docs give no numeric rate limits, and the status page lists 50 incidents in 85 days, mostly stale or degraded data.

**Weatherbit API.** A read-only weather API with a Swagger 2.0 spec, quota headers on every response and a status page showing 100 per cent on three API monitors over 90 days. The key travels only in the query string, the free plan allows 50 requests a day for non-commercial use, and the last dated API announcement is 1 August 2025.

## Before you call either

### Tomorrow.io Weather API

1. Send the key in the `apikey` header, not the query string, so it stays out of URLs and logs
2. Request only the `fields` and `timesteps` needed on POST /timelines. Free plans cover 24 hours back and 5 days ahead at `1h` and `1d`
3. Split archive requests. POST /historical takes at most 31 days per call and deducts tokens, 1 for a point and 10 for a polygon
4. Treat 401 with code 401001 as a missing or bad key. The docs say 403, the live API answered 401 on 8 October 2026
5. On 429 back off without a hint. `Retry-After` is documented only for 503
6. Check the plan's terms before storing or reselling responses. Free accounts are limited to non-commercial use with a Powered by Tomorrow.io link

### Weatherbit API

1. Pass lat and lon. City, postal code and station lookups are accepted, but the docs recommend coordinates and mark station ID as use with caution
2. Read X-RateLimit-Remaining and X-RateLimit-Reset on each response. Daily quotas reset at 00:00 UTC and a spent quota returns 429 until then
3. Treat HTTP 204 with an empty body as no data found, not as an error
4. Split historical requests into ranges of one month or less. History needs the Plus plan or higher and has its own daily quota
5. Keep the key out of logs. It is part of the URL on every call, so always use https://api.weatherbit.io/v2.0

## Questions

### Which is better for AI agents, Tomorrow.io Weather API or Weatherbit API?

Weatherbit API scores 57.7 (C) on agent readiness against Tomorrow.io Weather API's 51.4 (D), and leads in 3 of 7 scored categories. Tomorrow.io Weather API leads on agent ergonomics and maintenance & community.

### Do Tomorrow.io Weather API and Weatherbit API need an API key?

Tomorrow.io Weather API takes an API key or an OAuth sign-in. Weatherbit API needs an API key.

### Can an agent call Tomorrow.io Weather API and Weatherbit API without installing anything?

Yes. Tomorrow.io Weather API has a hosted endpoint at https://api.tomorrow.io/v4 and Weatherbit API at https://api.weatherbit.io/v2.0.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/tomorrow-io-vs-weatherbit.json, and with the fewest tokens: https://www.anchorterminal.com/compare/tomorrow-io-vs-weatherbit.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "tomorrow-io", "b": "weatherbit"}`. From a terminal: `anchor compare tomorrow-io weatherbit`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/tomorrow-io.json and https://www.anchorterminal.com/api/v1/tools/weatherbit.json

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