Every free weather forecast, one call MCP server

Which MCP servers are Every free weather forecast, one call's own, from the official registry and from asking its own domain, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-29

← Back to Every free weather forecast, one call

Whose server it is

Registry namemarkets.groundhog/weatherverified in the MCP registry

The registry name sits under groundhog.markets. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

When we asked itchecked 2026-10-29

Stateanswerschecked 2026-10-29
Tools8
Server calls itselfgroundhog
Server version1.2.0
Protocol version2025-06-18

On 2026-10-29 the server answered initialize and tools/list without a sign-in. First answer in 228 ms.

Should an agent connect itNot proven either way yet

Its tools do every use case we checked: compare forecasts against Kalshi or Polymarket weather markets; search any place for its weather forecast.
Checked on 5 of the 7 days it takes to judge reliability.

Once connected

For "search any place for its weather forecast", the likely first call is search.
Parameters are untyped or undescribed in 6 of 8 tools: check arguments before calling.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

Measured dailydaily checks: 5, the first on 2026-10-29

INITE MCP scoreafter a weeka score needs 7 daily checks: 5 so far
What an agent can do with it2 of 2 use cases
Answeredmeasuring5 of the 7 daily checks it takes to print a share
Median first answer248 ms
Space in an agent's context≈ 1,732 tokensthe definitions of all its tools (8), which an agent carries on every turn
Tool definitionsB · 88 of 100
Typed results0 of 8 toolsdeclared outputSchema: results come typed, read once

Parameters without a description: in 6 of 8

What an agent can do with it

not sure · check daily high, low and rain forecasts for 77 cities
can do · compare forecasts against Kalshi or Polymarket weather markets
can do · search any place for its weather forecast

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

None of the five warning signs in these definitions.

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (25%), doing the product's job (25%), definitions (20%), context (10%), use (10%) and how readily a client connects (10%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

Tools it offers8 tools · read 2026-10-29

forecast
Daily high/low for any place from every free forecast: median, spread, rain, current obs and active alerts, with credits and the page URL. line ≈321 tok, week ≈566, table ≈1,567, series ≈1,564. Keep the credits and link the page when you…
places
Find a place slug by name, City, ST, airport code or lat,lon; says full blend or grid only.
sources
Open sources groundhog uses: licence, latest run, age, status.
markets
Weather markets in a place (Kalshi, Polymarket high/low/rain): settlement station and rule, the number so far under that rule, our value and the official result once settled, forecast daily max/min at the station. No prices. Needs place…
receipts
How often our settle value matched the venue's result, with every miss. No prices.
search
Search places by name, City, ST, airport code or lat,lon. Returns {results: [{id, title, url, text}]}; pass an id to fetch.
fetch
The 7-day forecast of a place id from search: {id, title, text, url, metadata}. Keep the credits and link the url when you repeat numbers.
history
As-issued history for backtests (no look-ahead): kind=daily (every source's daily hi/lo/rain per run at a place), nbm (NBM text columns: TXN, XND, P12, Q12; view=day = the books' day view) or obs (settlement truth: CLI, routine-METAR…

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "weather": {
      "type": "http",
      "url": "https://groundhog.markets/mcp"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http groundhog https://groundhog.markets/mcp

Add to Cursor Add to VS Code

claude.ai, ChatGPT and other clients: add https://groundhog.markets/mcp as a custom connector in the settings.

OpenAPI spec

13 paths, read 2026-10-29. Open the spec ↗

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.