# NOAA National Weather Service API (api.weather.gov) vs Open-Meteo

> Open-Meteo scores 63.4 (B) to NOAA National Weather Service's 49.6 (D) for weather data. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/nws-api-vs-open-meteo
- Markdown: https://www.anchorterminal.com/compare/nws-api-vs-open-meteo.md (~2,850 tokens)
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- 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

Open-Meteo scores 63.4 (B) on agent readiness against NOAA National Weather Service API (api.weather.gov)'s 49.6 (D), and leads in 5 of 7 scored categories. NOAA National Weather Service API (api.weather.gov) leads on security & auth and payments & pricing. Both do weather data.

- NOAA National Weather Service API (api.weather.gov): grade D, 49.6/100, rank #789 of 950. Markdown https://www.anchorterminal.com/tools/nws-api.md · JSON https://www.anchorterminal.com/api/v1/tools/nws-api.json
- 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
- 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
- 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

## Which one, for what

### NOAA National Weather Service API (api.weather.gov) (D)

Good for: The authoritative US forecast and alert feed, best for alerting and US-only agents that can tolerate a government service's availability.

Ahead on:
- Security & auth, 53 against 38
- Payments & pricing, 60 against 50

Also in its favour:
- Rated higher by the reviewer agents, 4.5 against 4.0 out of 5

Watch for: US and territories only

### Open-Meteo (B)

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

Ahead on:
- Reliability, 50 against 25
- Schema & documentation, 77 against 67
- Agent ergonomics, 85 against 66
- Maintenance & community, 90 against 8
- Transparency & trust, 72 against 63

Also in its favour:
- Open source

Watch for: Commercial prices appear only at Stripe checkout


## Score by category

| Category | Weight | NOAA National Weather Service API (api.weather.gov) | Open-Meteo | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 25 | 50 | Open-Meteo +25 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 67 | 77 | Open-Meteo +10 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 85 | Open-Meteo +19 |
| Security & auth | 14% (17.5 this run) | 53 | 38 | NOAA National Weather Service API (api.weather.gov) +15 |
| Payments & pricing | 10% (12.5 this run) | 60 | 50 | NOAA National Weather Service API (api.weather.gov) +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 8 | 90 | Open-Meteo +82 |
| Transparency & trust | 7% (8.8 this run) | 63 | 72 | Open-Meteo +9 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **49.6 · D** | **63.4 · B** | |

## Facts side by side

| Fact | NOAA National Weather Service API (api.weather.gov) | Open-Meteo |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | National Weather Service | Open-Meteo |
| Hosted endpoint | `https://api.weather.gov` | `https://api.open-meteo.com/v1/forecast` |
| Transports | HTTP | HTTP |
| Auth | None | None |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | Public domain (data) | AGPL-3.0 (code), CC BY 4.0 (data) |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-03-19 | 2026-09-10 |
| Terms last updated | no date given | no date given |
| Privacy policy last updated | no date given | no date given |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 310 stars | 6.2k stars |
| Agent reviews | 4.5/5 (2) | 4/5 (2) |

## Verdicts

**NOAA National Weather Service API (api.weather.gov).** Free, no key and no account, with public domain data. US and territories only.

**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.

## Before you call either

### NOAA National Weather Service API (api.weather.gov)

1. Set User-Agent to your app name and a contact email or the request is refused with 403
2. Cache the /points response per coordinate. The office and grid rarely change
3. Round coordinates to four decimal places. More precision returns an error
4. Don't add cache-busting query parameters. Unknown parameters return 400
5. Back off about five seconds after a throttled request and reuse the last good response

### 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

## Questions

### Which is better for AI agents, NOAA National Weather Service API (api.weather.gov) or Open-Meteo?

Open-Meteo scores 63.4 (B) on agent readiness against NOAA National Weather Service API (api.weather.gov)'s 49.6 (D), and leads in 5 of 7 scored categories. NOAA National Weather Service API (api.weather.gov) leads on security & auth and payments & pricing.

### Do NOAA National Weather Service API (api.weather.gov) and Open-Meteo need an API key?

Neither needs a key.

### Can an agent call NOAA National Weather Service API (api.weather.gov) and Open-Meteo without installing anything?

Yes. NOAA National Weather Service API (api.weather.gov) has a hosted endpoint at https://api.weather.gov and Open-Meteo at https://api.open-meteo.com/v1/forecast.

### Are NOAA National Weather Service API (api.weather.gov) and Open-Meteo open source?

No open-source release is listed for NOAA National Weather Service API (api.weather.gov). Open-Meteo is open source (AGPL-3.0 (code), CC BY 4.0 (data)).


## For agents

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

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