Head to head · Weather forecasts · October 2026 research run

Meteosource Weather MCP vs Pirate Weather

Pirate Weather scores 65.7 (B) on agent readiness against Meteosource Weather MCP's 50.9 (D), and leads in 6 of 7 scored categories. Both do weather forecasts.

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

Pirate Weather B

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

Ahead on

  • Reliability, 75 against 35
  • Schema & documentation, 85 against 72
  • Maintenance & community, 80 against 70
  • Transparency & trust, 66 against 32

Also in its favour

  • Free to start without a card
  • Open source

Watch for

No SLA, and the terms call it best effort

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.

Reliability Pirate Weather +40

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.

Pirate Weather 75

Status page at pirateweather.xitoring.io, linked from the home page and the changelog. It rendered only with JavaScript on 1 October and answered our reader with a Cloudflare bot check on 1 November, so the award rests on the 30 September check that it exists (20). The project's own incident reports page, now at docs.pirateweather.net, is readable. In the last 90 days it records one incident, on 27 August 2026, when a cleanup job at the Apiable portal removed about 140 subscriptions and revoked their keys while the API itself stayed up, a partial incident (20). Limits published with numbers, 10,000 calls a month free and 20,000 on the $2 plan, with Ratelimit-Limit, Ratelimit-Remaining and Ratelimit-Reset headers (15). 429 means the monthly quota is spent and the reset header says when it clears, and the docs say to retry a 500. No backoff guidance beyond that, though every call is a GET (10 of 15). The terms say best effort with no warranty, so no SLA (0). Version 2 of the API is the stable default (10).

Transparency & trust Pirate Weather +34

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.

Pirate Weather 66

The API code is AGPL-3.0 and the docs and OpenAPI spec are Apache-2.0. We took 5 off the 30 because the terms say nothing about reusing response data (25 of 30). The privacy notice is a generator template last updated 23 September 2024, with retention 'as long as necessary' and no DPA. It agrees with itself but says little (12 of 30). Version 1 and 2 response shapes are both kept, and the changelog dates every change, but there's no written deprecation policy (10 of 20). The privacy notice names Apiable and Stripe, and the infrastructure blog posts name AWS ECS, Aurora PostgreSQL and Kong, but no data locations are stated (8 of 20).

Schema & documentation Pirate Weather +13

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.

Pirate Weather 85

OpenAPI 3.1.0 spec in the docs repository, versioned 2.10.3 to match the API since 20 October 2026, with 18 parameters and 400, 401, 404, 429, 500 and 502 responses on the forecast path (25). No llms.txt (404 on docs.pirateweather.net), though the Markdown sources of the docs are public on GitHub (5 of 10). The API docs and data-sources page explain each block and which model fills each field. The 11 MCP tool docstrings are one line each, with no when-not-to-use (14 of 20). The spec has five enums and leaves exclude and include as comma strings. The MCP tools use Pydantic types with bounded latitude, longitude and day counts and enumerated units and languages (11 of 15). A full response example page, 292 example values in the spec and every error code explained (15). Semantic API versions and a dated changelog with a pull request behind every line (15).

Maintenance & community Pirate Weather +10

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.

Pirate Weather 80

Version 2.10.3 on 21 October 2026 (30). Four releases in the last 90 days, 2.10.0, 2.10.1 and 2.10.2 between 18 and 23 September and 2.10.3 on 21 October (20). Open issues per the 1 October check, not re-read on 1 November because GitHub's pages refuse our reader. 32 were open then, labelled and triaged, most of them requests for new capabilities or data sources, with two portal bugs marked 'awaiting developer response' since May and a new-account key error (#656) open since 7 July (20 of 25). The hosted MCP server isn't in the official registry, where only a third-party Pipeworx wrapper (0.2.0) appears, and there's no official SDK (0). Dependabot, CodeQL and test workflows on the code repository, with dependency bumps merged on 26 October and 1 November 2026 (10).

Score by category

CategoryWeight this runMeteosource Weather MCPPirate WeatherEdge
Reliability16%203575Pirate Weather +40
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27285Pirate Weather +13
Agent ergonomics13%16.27577Pirate Weather +2
Security & auth14%17.54245Pirate Weather +3
Payments & pricing10%12.53030even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87080Pirate Weather +10
Transparency & trust7%8.83266Pirate Weather +34
Negative events≤1500
TotalD 50.9/100B 65.7/100

Facts side by side

FactMeteosource Weather MCPPirate Weather
KindMCP serverHTTP API
VendorMeteosourcePirate Weather
Hosted endpointhttps://mcp.meteosource.com/mcphttps://api.pirateweather.net/forecast
TransportsStreamable HTTPHTTP, Streamable HTTP
AuthAPI keyAPI key
PricingFreemiumFreemium
x402nono
LicenceProprietary service. The repository's MIT licence covers its docs and manifestApache-2.0 (docs and spec), AGPL-3.0 (API code)
Tools exposed7none
Read-only variant documentednono
llms.txtnono
MCP registrycom.meteosource/weathernot listed
Last releasenone2026-10-21
Terms last updatedno document linkednot read yet
Privacy policy last updatedno document linkednot read yet
Popularitynone907 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.

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

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

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, Meteosource Weather MCP or Pirate Weather?

Pirate Weather scores 65.7 (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 Pirate Weather need an API key?

Both need an API key.

Can an agent call Meteosource Weather MCP and Pirate Weather without installing anything?

Yes. Meteosource Weather MCP has a hosted endpoint at https://mcp.meteosource.com/mcp and Pirate Weather at https://api.pirateweather.net/forecast.

Are Meteosource Weather MCP and Pirate Weather open source?

No open-source release is listed for Meteosource Weather MCP. Pirate Weather is open source (Apache-2.0 (docs and spec), AGPL-3.0 (API code)).

Other comparisons with Meteosource Weather MCP or Pirate Weather

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