MeteoSwiss Open Data — Python API, CLI, MCP server, Parquet & Delta tables

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foehn downloads every MeteoSwiss OGD collection via the STAC API, converts CSV/TXT to Parquet with Polars, and optionally ingests everything into Databricks Unity Catalog Delta tables on a daily schedule. It also ships an MCP server so LLMs can query Swiss weather data directly.

Daily weather in Bern, powered by foehn's MCP server and MeteoSwiss open data.

Why foehn?

• 20+ collections in one command — weather stations, radar, hail maps, forecasts, climate scenarios, and more
• MCP server for LLMs — give your favorite LLM live access to MeteoSwiss data with the MCP server
• Significantly smaller on disk — columnar Parquet with Zstandard compression vs. raw CSVs
• Incremental by default — only re-downloads files that changed since your last run, tracked via _last_run.json
• No Spark required locally — download + conversion uses Polars only; Spark is optional for Delta ingestion
• Ships a Declarative Automation Bundle — ready-to-deploy daily job and historical backfill, no pipeline config needed

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Quick start

pip install foehn
foehn download

Recent data (Jan 1 to yesterday) is downloaded and converted to Parquet under ./data/meteoswiss/.

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Installation

From PyPI:

pip install foehn

From source:

git clone https://github.com/kayhendriksen/foehn
cd foehn
pip install -e .

With extras:

pip install "foehn[databricks]"   # PySpark + Delta
pip install "foehn[mcp]"          # MCP server

Requires Python 3.10 or later.

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Python API

import foehn

df = foehn.load("smn", station="BER", frequency="d")

Load data directly into Polars DataFrames, explore metadata, download to disk, and convert to Parquet — all from Python. See the full Python API documentation.

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CLI

foehn download smn pollen
foehn load smn --station BER --frequency d

The CLI mirrors the Python API with subcommands for downloading, converting, loading, and inspecting metadata. See the full CLI documentation.

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MCP server

{
  "mcpServers": {
    "foehn": {
      "command": "foehn",
      "args": ["mcp"]
    }
  }
}

Give any MCP-compatible LLM live access to MeteoSwiss data. See the full MCP server documentation.

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Documentation

Collections	All 20+ MeteoSwiss datasets, categories, and time slice conventions
Python API	Loading data, metadata, downloading, and Parquet conversion
CLI	All subcommands, flags, and environment variables
MCP Server	Setup, configuration, and available tools
Databricks Pipeline	Declarative Automation Bundle deployment

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Data sources

STAC API	https://data.geo.admin.ch/api/stac/v1
Documentation	https://opendatadocs.meteoswiss.ch
MeteoSwiss OGD	https://github.com/MeteoSwiss/opendata

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License

MIT