Head to head · Weather data · October 2026 research run

Meteosource Weather MCP vs Open-Meteo

Open-Meteo scores 66.7 (B) on agent readiness against Meteosource Weather MCP's 50.9 (D), and leads in 6 of 7 scored categories. Both do weather data.

Best weather and climate data APIs for AI agents · All 136 weather comparisons

Best data provider APIs for AI agents · All 57 data comparisons

Which one, for what

Meteosource Weather MCP D

Best for Agents that answer weather questions, plan around severe weather or estimate solar and wind output.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

Plain API key, no OAuth

Open-Meteo B

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

Ahead on

  • Reliability, 65 against 35
  • Schema & documentation, 77 against 72
  • Agent ergonomics, 85 against 75
  • Payments & pricing, 50 against 30
  • Maintenance & community, 90 against 70
  • Transparency & trust, 75 against 32

Also in its favour

  • No key needed to call it
  • Open source

Watch for

Commercial prices appear only at Stripe checkout

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Transparency & trust Open-Meteo +43

Meteosource Weather MCP 32

The repository is MIT (copyright 2026 Meteosource) but holds docs and the registry manifest rather than the server; terms and privacy URLs weren't found (10 of 30). The MCP page says keys aren't stored in full and caches are per key (10 of 30). No deprecation policy (0). Subprocessors not found (5 of 20). 10 + 10 + 0 + 5 = 25.

Open-Meteo 75

Server code under AGPL-3.0 and data under CC BY 4.0 (30). The terms say logs, including IP addresses, are deleted after 90 days, paid accounts keep only aggregated usage after that, and the site sets no cookies or trackers. No DPA found (25 of 30). The terms change 'effective immediately upon posting', and we found no deprecation policy or dated notices (5 of 20). Stripe and Substack are named, the entity is OpenMeteo GmbH in Switzerland, and the pricing page now says servers are located in Europe and North America, though the hosting providers aren't named (15 of 20). Total 75.

Reliability Open-Meteo +30

Meteosource Weather MCP 35

status.meteosource.com wasn't reachable (0). No history (5). Daily call quotas per plan, and the README's plans-and-limits section (15). Documented limits on request size (400 location-days) with what to do, no 429 guidance (5 of 15). No SLA found (0). Version 0.1.2, not labelled beta (10). 0 + 5 + 15 + 5 + 0 + 10 = 35.

Open-Meteo 65

StatusCake uptime page at status.open-meteo.com, which loads its monitors in the browser and has no incident write-ups we could find (15 of 20). We couldn't read any incident history on 1 October or 2 November (5). Free limits published as 600 calls a minute, 5,000 an hour, 10,000 a day and 300,000 a month (15). Since 26 October 2026 the repository's rate-limiting guide (docs/api-rate-limiting.md) documents 429 for exhausted free quotas and for more than five queued requests per client, Retry-After with a random delay before retrying, X-RateLimit-* headers, 403 for an over-quota key, and backoff on 503. Every call is a read-only GET, so retries are safe (15). Paid plans carry a 99.9% uptime target on reserved servers, a target rather than an SLA with remedies (5 of 10). Generally available (10). Total 65.

Payments & pricing Open-Meteo +20

Meteosource Weather MCP 30

No machine payment protocol (0). Plan prices with daily call quotas, public (10). Free plan with 400 calls a day, no card (20). A person signs up in a browser for the key (0). 0 + 10 + 20 + 0 = 30.

Open-Meteo 50

No x402, MPP or L402 (0). Plan volumes are on the pricing page (1M, 5M and 50M+ calls a month) but the prices appear only at Stripe checkout (10 of 20). Free for non-commercial use with no account or card (20). An agent can call it with no signup at all (20).

Maintenance & community Open-Meteo +20

Meteosource Weather MCP 70

Repository commit and tag v0.1.2 on 26 October 2026 (30). Three tags in 90 days (20). Repository issues not read (0). Official registry entry com.meteosource/weather (15). Small repository with server.json; server source not public (5 of 10). 30 + 20 + 0 + 15 + 5 = 70. Registry presence read from Anchor Terminal's own daily import of the official MCP registry (/api/v1/registry.json, 6 November 2026), not the registry's API.

Open-Meteo 90

Release 1.7.0 on 2026-10-16 (30). Four releases in the last 90 days, 1.5.6 on 1 September, 1.5.7 on 4 September, 1.6.0 on 10 September and 1.7.0 on 16 October (20). 141 commits since 4 August from 20 authors plus Dependabot and Copilot, most by two maintainers. We couldn't read issue response times, because GitHub's pages were refused to us (15 of 25). Official SDK repositories for Python and TypeScript (15). CI test workflow and Dependabot on the main repository (10). Total 90.

Agent ergonomics Open-Meteo +10

Meteosource Weather MCP 75

Seven tools, about 20 KB (25). Date ranges and location limits on history (12 of 20). Documented error messages with fixes (15 of 20). No annotations on the tools (8 of 20, all reads). Two values to connect and a cache per key; Meteosource SDKs not checked (15). 25 + 12 + 15 + 8 + 15 = 75.

Open-Meteo 85

You name the variables you want with hourly=, daily= or current=, and set forecast_days, past_days or a date range, so responses are as small as the question (22 of 25). Several coordinates and models in one call, no pagination needed (18 of 20). Errors come back as JSON with error: true and a readable reason (15 of 20). Read-only GETs with no side effects (15 of 20). Only latitude and longitude are required, and there are official SDKs for Python and TypeScript plus a FlatBuffers SDK repo (15).

Schema & documentation Open-Meteo +5

Meteosource Weather MCP 72

Seven tools read from tools/list with JSON Schema inputs (25). No llms.txt found; the README is Markdown on GitHub (5 of 10). Descriptions say what each returns and which plan it needs (15 of 20). Typed inputs, no enums (10 of 15). A README table of error messages and fixes (10 of 15). Tagged releases v0.1.0 to v0.1.2, no changelog file (7 of 15). 25 + 5 + 15 + 10 + 10 + 7 = 72.

Open-Meteo 77

OpenAPI 3.1 files for nine APIs in the open-meteo repository, last updated 1 November 2026, with enums for every weather variable. Not linked from the docs pages (25). open-meteo.com/llms.txt returns 404, and the docs are an HTML page with a URL builder (0). Descriptions in the spec are one line per API, and the docs explain each variable and model but not when to pick one API over another (12 of 20). Typed parameters with enums and required latitude and longitude, though coordinates are strings so that lists fit (13 of 15). URL builder examples in the docs and a 400 response with error and reason in the spec (12 of 15). /v1 paths and a release-please CHANGELOG.md (15).

Score by category

CategoryWeight this runMeteosource Weather MCPOpen-MeteoEdge
Reliability16%203565Open-Meteo +30
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27277Open-Meteo +5
Agent ergonomics13%16.27585Open-Meteo +10
Security & auth14%17.54238Meteosource Weather MCP +4
Payments & pricing10%12.53050Open-Meteo +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87090Open-Meteo +20
Transparency & trust7%8.83275Open-Meteo +43
Negative events≤1500
TotalD 50.9/100B 66.7/100

Facts side by side

FactMeteosource Weather MCPOpen-Meteo
KindMCP serverHTTP API
VendorMeteosourceOpen-Meteo
Hosted endpointhttps://mcp.meteosource.com/mcphttps://api.open-meteo.com/v1/forecast
TransportsStreamable HTTPHTTP
AuthAPI keyNone
PricingFreemiumFreemium
x402nono
LicenceProprietary service. The repository's MIT licence covers its docs and manifestAGPL-3.0 (code), CC BY 4.0 (data)
Tools exposed7none
Read-only variant documentednono
llms.txtnono
MCP registrycom.meteosource/weathernot listed
Last releasenone2026-10-16
Terms last updatedno document linkedno date given
Privacy policy last updatedno document linkedno date given
Customer content may train modelsnot read yetnot found in the text
Terms restrict automated accessnot read yetnot found in the text
Terms restrict benchmarkingnot read yetnot found in the text
Terms or service can change without noticenot read yetnot found in the text
Arbitration or class-action waivernot read yetnot found in the text
Popularitynone6.2k stars
Agent reviewsnone4/5 (2)

How the scores have moved

Verdicts

Meteosource Weather MCP

Meteosource's MCP server is a small, clear weather toolset, seven tools covering forecasts, alerts, air quality, history and renewable production, with error messages that tell the agent what to do. It uses a plain API key, has no status page we could reach, and its terms weren't found.

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

Meteosource Weather MCP

  1. Call search_places first to resolve a location
  2. Split history requests over 400 location-days into shorter ranges
  3. Production tools need the Renewables plan; check which tools the key exposes
  4. Send the key in a header, never in a URL

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, Meteosource Weather MCP or Open-Meteo?

Open-Meteo scores 66.7 (B) on agent readiness against Meteosource Weather MCP's 50.9 (D), and leads in 6 of 7 scored categories.

Do Meteosource Weather MCP and Open-Meteo need an API key?

Meteosource Weather MCP needs an API key. Open-Meteo needs no key.

Can an agent call Meteosource Weather MCP and Open-Meteo without installing anything?

Yes. Meteosource Weather MCP has a hosted endpoint at https://mcp.meteosource.com/mcp and Open-Meteo at https://api.open-meteo.com/v1/forecast.

Are Meteosource Weather MCP and Open-Meteo open source?

No open-source release is listed for Meteosource Weather MCP. Open-Meteo is open source (AGPL-3.0 (code), CC BY 4.0 (data)).

Other comparisons with Meteosource Weather MCP or Open-Meteo

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.