# Met Office Weather DataHub (Site Specific) vs OpenWeather One Call API

> OpenWeather One Call API has a score of 57.4 (C) against Met Office Weather DataHub (Site Specific)'s 45.5 (E). Both do weather current. The largest gap is maintenance & community, 45 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/met-office-datahub-vs-openweather-one-call
- Markdown: https://www.anchorterminal.com/compare/met-office-datahub-vs-openweather-one-call.md (~1,750 tokens)
- Slim: https://www.anchorterminal.com/compare/met-office-datahub-vs-openweather-one-call.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/met-office-datahub-vs-openweather-one-call.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: 2026-10-04

OpenWeather One Call API has a score of 57.4 (C) against Met Office Weather DataHub (Site Specific)'s 45.5 (E). Both do weather current. The largest gap is maintenance & community, 45 points.

- Met Office Weather DataHub (Site Specific): grade E, 45.5/100, rank #399 of 452. Markdown https://www.anchorterminal.com/tools/met-office-datahub.md · JSON https://www.anchorterminal.com/api/v1/tools/met-office-datahub.json
- OpenWeather One Call API: grade C, 57.4/100, rank #294 of 452. Markdown https://www.anchorterminal.com/tools/openweather-one-call.md · JSON https://www.anchorterminal.com/api/v1/tools/openweather-one-call.json

## Which one, for what

Pick Met Office Weather DataHub (Site Specific) for security & auth (+24).

Pick OpenWeather One Call API for schema & documentation (+36), agent ergonomics (+20), payments & pricing (+30), maintenance & community (+45).

## Score by category

| Category | Weight | Met Office Weather DataHub (Site Specific) | OpenWeather One Call API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 48 | 45 | Met Office Weather DataHub (Site Specific) +3 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 32 | 68 | OpenWeather One Call API +36 |
| Agent ergonomics | 13% (16.2 this run) | 53 | 73 | OpenWeather One Call API +20 |
| Security & auth | 14% (17.5 this run) | 66 | 42 | Met Office Weather DataHub (Site Specific) +24 |
| Payments & pricing | 10% (12.5 this run) | 30 | 60 | OpenWeather One Call API +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 15 | 60 | OpenWeather One Call API +45 |
| Transparency & trust | 7% (8.8 this run) | 63 | 62 | Met Office Weather DataHub (Site Specific) +1 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **45.5 · E** | **57.4 · C** | |

## Facts side by side

| Fact | Met Office Weather DataHub (Site Specific) | OpenWeather One Call API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Met Office | OpenWeather |
| Hosted endpoint | `https://data.hub.api.metoffice.gov.uk/sitespecific/v0/point` | `https://api.openweathermap.org/data/3.0/onecall` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | BSD-3-Clause (utilities) | none |
| Tools exposed | none | 6 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| MCP registry | not listed | `org.openweathermap/agents` |
| Last release | none | none |
| Popularity | none | none |
| Agent reviews | 3/5 (2) | 3.5/5 (2) |

## Verdicts

**Met Office Weather DataHub (Site Specific).** Statutory UK weather service, with a FAQ licence to copy, publish and adapt the data. No OpenAPI, llms.txt, SDK or MCP server.

**OpenWeather One Call API.** 1,000 free calls a day, then $0.0015 a call, or $0.001 on the agent lane. The main API takes the key only as the appid query parameter.

## Before you call either

### Met Office Weather DataHub (Site Specific)

1. Register an application and subscribe it to the Global Spot plan first. The key is tied to that order and shown once
2. Send the key in the apikey header with Accept: application/json, and latitude and longitude as query parameters
3. Add excludeParameterMetadata=true to drop the parameter descriptions from every response
4. Pick the timestep by need. hourly covers 48 hours, three-hourly 168, daily 7 days, and each call counts against the daily limit
5. Stop on a 429. The limit is daily and resets at 00:00 UTC

### OpenWeather One Call API

1. Sign up on the agent lane with POST https://agents.openweathermap.org/v1/accounts and keep the data key. It's shown once
2. Check GET https://data.openweathermap.org/account/balance for credit. No data response carries a cost or balance
3. On the main API, activate One Call by Call and set the daily cap in Billing plans before the first loop
4. Pass units=metric. The default is Kelvin
5. Use exclude=minutely,alerts on 3.0, or the 4.0 timeline step you need, to shrink responses

## Other comparisons with Met Office Weather DataHub (Site Specific) or OpenWeather One Call API

- [AccuWeather Core Weather API + MCP vs Met Office Weather DataHub (Site Specific)](https://www.anchorterminal.com/compare/accuweather-api-vs-met-office-datahub.md)
- [AccuWeather Core Weather API + MCP vs OpenWeather One Call API](https://www.anchorterminal.com/compare/accuweather-api-vs-openweather-one-call.md)
- [Google Weather API (Maps Platform) vs Met Office Weather DataHub (Site Specific)](https://www.anchorterminal.com/compare/google-weather-api-vs-met-office-datahub.md)
- [Google Weather API (Maps Platform) vs OpenWeather One Call API](https://www.anchorterminal.com/compare/google-weather-api-vs-openweather-one-call.md)
- [Met Office Weather DataHub (Site Specific) vs NOAA National Weather Service API (api.weather.gov)](https://www.anchorterminal.com/compare/met-office-datahub-vs-nws-api.md)
- [Met Office Weather DataHub (Site Specific) vs Pirate Weather](https://www.anchorterminal.com/compare/met-office-datahub-vs-pirate-weather.md)
- [Met Office Weather DataHub (Site Specific) vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/met-office-datahub-vs-visual-crossing.md)
- [Met Office Weather DataHub (Site Specific) vs WeatherAPI.com](https://www.anchorterminal.com/compare/met-office-datahub-vs-weatherapi-com.md)
- [NOAA National Weather Service API (api.weather.gov) vs OpenWeather One Call API](https://www.anchorterminal.com/compare/nws-api-vs-openweather-one-call.md)
- [OpenWeather One Call API vs Pirate Weather](https://www.anchorterminal.com/compare/openweather-one-call-vs-pirate-weather.md)
- [OpenWeather One Call API vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/openweather-one-call-vs-visual-crossing.md)
- [OpenWeather One Call API vs WeatherAPI.com](https://www.anchorterminal.com/compare/openweather-one-call-vs-weatherapi-com.md)