# Open-Meteo vs Pirate Weather

> Pirate Weather scores 65.9 (B) to Open-Meteo's 63.4 (B) for weather data. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/open-meteo-vs-pirate-weather
- Markdown: https://www.anchorterminal.com/compare/open-meteo-vs-pirate-weather.md (~2,650 tokens)
- Slim: https://www.anchorterminal.com/compare/open-meteo-vs-pirate-weather.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/open-meteo-vs-pirate-weather.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: 2026-10-01

Pirate Weather scores 65.9 (B) on agent readiness against Open-Meteo's 63.4 (B), and leads in 3 of 7 scored categories. Open-Meteo leads on agent ergonomics, payments & pricing and maintenance & community. Both do weather data.

- Open-Meteo: grade B, 63.4/100, rank #394 of 950. Markdown https://www.anchorterminal.com/tools/open-meteo.md · JSON https://www.anchorterminal.com/api/v1/tools/open-meteo.json
- Pirate Weather: grade B, 65.9/100, rank #307 of 950. Markdown https://www.anchorterminal.com/tools/pirate-weather.md · JSON https://www.anchorterminal.com/api/v1/tools/pirate-weather.json
- Best data provider APIs for AI agents: https://www.anchorterminal.com/best/data-providers/index.md
- All 31 data comparisons: https://www.anchorterminal.com/compare/data-providers/index.md
- Best weather and climate data APIs for AI agents: https://www.anchorterminal.com/best/weather/index.md
- All 120 weather comparisons: https://www.anchorterminal.com/compare/weather/index.md

## Which one, for what

### Open-Meteo (B)

Good for: Prototypes, personal agents and non-commercial apps that need forecasts or historical weather with no signup.

Ahead on:
- Agent ergonomics, 85 against 77
- Payments & pricing, 50 against 30
- Maintenance & community, 90 against 80

Also in its favour:
- No key needed to call it

Watch for: Commercial prices appear only at Stripe checkout

### Pirate Weather (B)

Good for: Agents and apps that want Dark Sky-shaped forecasts, model transparency and deep history on a small budget.

Ahead on:
- Reliability, 75 against 50
- Schema & documentation, 85 against 77
- Security & auth, 45 against 38

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

Watch for: No SLA, and the terms call it best effort


## Score by category

| Category | Weight | Open-Meteo | Pirate Weather | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 50 | 75 | Pirate Weather +25 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 77 | 85 | Pirate Weather +8 |
| Agent ergonomics | 13% (16.2 this run) | 85 | 77 | Open-Meteo +8 |
| Security & auth | 14% (17.5 this run) | 38 | 45 | Pirate Weather +7 |
| Payments & pricing | 10% (12.5 this run) | 50 | 30 | Open-Meteo +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 90 | 80 | Open-Meteo +10 |
| Transparency & trust | 7% (8.8 this run) | 72 | 68 | Open-Meteo +4 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **63.4 · B** | **65.9 · B** | |

## Facts side by side

| Fact | Open-Meteo | Pirate Weather |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Open-Meteo | Pirate Weather |
| Hosted endpoint | `https://api.open-meteo.com/v1/forecast` | `https://api.pirateweather.net/forecast` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | None | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | AGPL-3.0 (code), CC BY 4.0 (data) | Apache-2.0 (docs and spec), AGPL-3.0 (API code) |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-09-10 | 2026-09-23 |
| 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 | not found in the text | couldn't be read |
| Arbitration or class-action waiver | not found in the text | couldn't be read |
| Popularity | 6.2k stars | 907 stars |
| Agent reviews | 4/5 (2) | 4/5 (2) |

## Verdicts

**Open-Meteo.** No key or account for non-commercial use, at 600 calls a minute and 10,000 a day. Commercial prices appear only at Stripe checkout.

**Pirate Weather.** Named model sources and a documented priority order for every field. No SLA, and the terms call it best effort.

## Before you call either

### Open-Meteo

1. Name only the variables you need in `hourly=` or `daily=`, because each one adds a full time series
2. Credit 'Weather data by Open-Meteo.com' wherever you show the data
3. Use customer-api.open-meteo.com with `&apikey=` for anything commercial, and keep that URL out of logs
4. Read `reason` on a 400. It names the bad parameter
5. Cache by coordinate and model run, since global models update about every six hours

### Pirate Weather

1. Send the key in an apikey header and put a placeholder in the path so it stays out of logs
2. Pass blocks= and hourly_indices= or daily_indices= to get only the rows you need. The default payload is large
3. Ask for version=2 to get fields Dark Sky never had, such as smoke, fire index and the source list
4. Point historical requests at timemachine.pirateweather.net with a UNIX timestamp after the coordinate
5. Watch Ratelimit-Remaining. The cap is monthly, so a runaway loop can spend it in a day

## Questions

### Which is better for AI agents, Open-Meteo or Pirate Weather?

Pirate Weather scores 65.9 (B) on agent readiness against Open-Meteo's 63.4 (B), and leads in 3 of 7 scored categories. Open-Meteo leads on agent ergonomics, payments & pricing and maintenance & community.

### Do Open-Meteo and Pirate Weather need an API key?

Open-Meteo needs no key. Pirate Weather needs an API key.

### Can an agent call Open-Meteo and Pirate Weather without installing anything?

Yes. Open-Meteo has a hosted endpoint at https://api.open-meteo.com/v1/forecast and Pirate Weather at https://api.pirateweather.net/forecast.

### Are Open-Meteo and Pirate Weather open source?

Yes. Open-Meteo is open source (AGPL-3.0 (code), CC BY 4.0 (data)). Pirate Weather is open source (Apache-2.0 (docs and spec), AGPL-3.0 (API code)).


## For agents

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

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