Open-Meteo weather API for MCP tools

The Open-Meteo weather API returns forecasts, historical weather, and air quality data as JSON over HTTP. Open-Meteo documents free access for non-commercial use without an API key at https://open-meteo.com/. An MCP tool wraps one endpoint so an AI agent can request the weather for a latitude and longitude and read the result.

What the Open-Meteo API returns

The forecast endpoint returns hourly and daily values as JSON. The request names the variables it needs, such as temperature_2m and precipitation_probability, in the hourly or daily parameter.

Each variable arrives as an array. The array lines up with a parallel time array, so the value at index 0 belongs to the first timestamp. An agent reads both arrays together and never guesses the time of a value.

The response also reports the coordinates it used and the elevation of the grid cell. Check these fields when the agent answers a question about a specific town. The grid cell can differ from the exact point.

Three endpoints an agent can call

Open-Meteo exposes several weather services. Three cover most agent workloads:

• The forecast endpoint returns values for the coming days.
• The historical archive returns observed weather for past dates.
• The air quality endpoint returns pollutant readings for the same coordinates.

Pick one endpoint per tool. A tool that covers one job gives the agent a clear choice. A tool that mixes forecast, archive, and air quality forces the agent to sort out which fields apply.

Wrap one endpoint as an MCP tool

An MCP tool needs a name, a description, and an input schema. The schema declares latitude, longitude, and the forecast window. The tool calls the Open-Meteo endpoint with those values and returns the JSON body.

Write the description with care. The agent reads it to decide when to call the tool. A vague description leads the agent to guess coordinates, and a wrong guess returns weather for the wrong place.

Limit the schema to the fields the agent needs. Each extra field adds a decision point and a chance for a malformed call.

APIbase lists weather tools in its catalog. Connect your agent at /connect to give your agent weather without writing the HTTP layer yourself.

Request parameters that cause errors

Three parameter mistakes account for most failed weather calls:

• Latitude and longitude must be decimal degrees. For Berlin, send latitude=52.52 and longitude=13.41.
• Set the timezone parameter to auto or to an IANA zone name such as Europe/Berlin. Otherwise the API returns timestamps in GMT, and the agent reports the wrong local hour.
• Variable names must match the documented spelling. A misspelled hourly variable returns an error or an empty field.

Validate the coordinates before the request leaves the agent. A check that rejects out-of-range values costs less than a failed call.

Pricing and access on APIbase

The listed price for weather tools ranges from 0 to 29.99 USD. The tool page shows the exact price before you connect.

Open-Meteo's free access covers non-commercial use. Commercial workloads follow the paid terms. Confirm the current limits at https://open-meteo.com/ before you ship a product that depends on the data.

When another weather API fits better

Pick a different provider when your product needs a contractual uptime guarantee or official severe weather alerts. Confirm coverage in each provider's documentation before you commit to one.

Open-Meteo suits agents that answer forecast, history, and air quality questions. Teams that need a service-level agreement should compare providers on that term first.

Live pricing — weather

Connect via MCP

$ curl -X POST https://apibase.pro/api/v1/tools/airnow.current_latlng/call \
  -H "Content-Type: application/json" -d '{"params": {}}'

FAQ

Does the Open-Meteo weather API need an API key?

For non-commercial use, Open-Meteo documents access without a key at https://open-meteo.com/. Commercial use follows its paid terms.

Can an AI agent call the Open-Meteo API through MCP?

Yes. Wrap one endpoint in an MCP tool with a schema for latitude and longitude. The agent calls the tool and reads the JSON response.

What format does the Open-Meteo response use?

The response uses JSON over HTTP. Each variable arrives as an array that lines up with a parallel time array.

What does an Open-Meteo weather tool cost on APIbase?

The listed price for weather tools ranges from 0 to 29.99 USD. The tool page shows the exact price.

Recommended next step

1. STEP 1/2 Connect your MCP client
2. STEP 2/2 Browse the full catalog

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Written with AI assistance from APIbase's published documentation and public data; checked automatically against them. Corrections: https://apibase.pro/

Published: 2026-11-05Source: live apibase.pro catalog snapshot