atmchile

Python library to download air quality and climate data from two Chilean government monitoring networks: SINCA (Sistema de Información Nacional de Calidad del Aire), operated by the Ministry of Environment of Chile (MMA — Ministerio del Medio Ambiente), and DMC (Dirección Meteorológica de Chile). Both modules return tidy pandas DataFrames with download-lineage columns, and support synchronous and asynchronous bulk downloads.

Installation

pip install atmchile

Quick Start

from datetime import datetime
from atmchile import ChileAirQuality

caq = ChileAirQuality()
df = caq.get_data(
    stations="RM/D14",
    parameters=["PM10", "PM25"],
    start=datetime(2020, 1, 1),
    end=datetime(2020, 1, 31),
)
print(df.head())

Available Parameters

ChileAirQuality (SINCA)

Units: µg/m³N = micrograms per normal cubic metre (0 °C, 1 atm); ppb = parts per billion by volume.

ChileClimateData (DMC)

Usage

ChileAirQuality

from datetime import datetime
from atmchile import ChileAirQuality

caq = ChileAirQuality()

data = caq.get_data(
    stations="El Bosque",
    parameters=["PM10", "PM25"],
    start=datetime(2020, 1, 1),
    end=datetime(2020, 1, 2),
)
print(data)

import asyncio
from datetime import datetime
from atmchile import ChileAirQuality

async def main():
    caq = ChileAirQuality(max_concurrent_downloads=5)

    data = await caq.get_data_async(
        stations=["RM", "II"],
        parameters=["PM10", "PM25"],
        start=datetime(2020, 1, 1),
        end=datetime(2021, 12, 31),
        region=True,
    )
    print(data)

asyncio.run(main())

ChileClimateData

from datetime import datetime
from atmchile import ChileClimateData

ccd = ChileClimateData()

data = ccd.get_data(
    stations="180005",
    parameters=["Temperatura", "Humedad"],
    start=datetime(2020, 1, 1, 0, 0, 0),
    end=datetime(2020, 12, 31, 23, 0, 0),
)
print(data)

import asyncio
from datetime import datetime
from atmchile import ChileClimateData

async def main():
    ccd = ChileClimateData(max_concurrent_downloads=5)

    data = await ccd.get_data_async(
        stations=["RM", "II"],
        parameters=["Temperatura", "PresionQFE"],
        start=datetime(2020, 1, 1, 0, 0, 0),
        end=datetime(2021, 12, 31, 23, 0, 0),
        region=True,
    )
    print(data)

asyncio.run(main())

Output columns & data lineage

Every DataFrame includes dl.* lineage columns alongside measurement values, recording the download and curation status of each individual data point. For the full column schema, dl.* status values, curation rules, and validation tiers for both classes, see docs/output-columns.md.

Data Sources

SINCA — air quality

SINCA (Sistema de Información Nacional de Calidad del Aire) is Chile's national air quality monitoring network, operated by the Ministry of Environment (MMA). It covers 120+ stations distributed across the country's administrative regions, measuring hourly concentrations of criteria pollutants and meteorological variables.

DMC — climate

DMC (Dirección Meteorológica de Chile) is Chile's national weather service, operated by the Dirección General de Aeronáutica Civil (DGAC). It provides synoptic climate observations (temperature, dew point, humidity, wind, surface and sea-level pressure) from stations nationwide.

Development

Run tests

# Run all tests
uv run pytest

# Run with more verbosity
uv run pytest -v

# Run tests with coverage (minimum threshold 90%)
uv run test-cov

Refresh station metadata

uv run refresh-stations

Fetches the current station list from the SINCA listadomapa2k19 endpoint and overwrites src/atmchile/data/sinca_stations.csv. Run this whenever SINCA adds or removes stations. The command prints a summary of stations written and a UTC timestamp.

If any station has an unrecognised region string, a WARNING line is printed and the station is written with region='UNKNOWN' so data loss is visible rather than silent. In that case, update REGION_MAP in src/atmchile/scripts.py before committing the refreshed CSV.

Linting and formatting

uv run ruff check . --fix
uv run ruff format .

Update dependencies

uv lock --upgrade && uv sync --all-extras

SINCA internals

SINCA has no publicly documented API. This library accesses data through reverse-engineered endpoints of the underlying Airviro platform. For details on backend architecture, station metadata discovery, parameter code mapping, URL construction, and response format, see docs/sinca-internals.md.

Attribution & AI Disclosure

This library is a Python port of the AtmChile R package by Francisco Menares et al., developed at the Department of Chemistry, Faculty of Sciences, Universidad de Chile. The original work was funded by ANID/FONDECYT Grant No. 1200674 (Fondo Nacional de Desarrollo Científico y Tecnológico, Chile's national research funding agency).

The original package is described in:

Menares et al. (2022). The AtmChile Open-Source Interactive Application for Exploring Air Quality and Meteorological Data in Chile. Atmosphere, 13(9), 1364.

The initial R-to-Python port was generated with the assistance of Claude (Anthropic) AI. Subsequent architecture decisions, testing, and incremental improvements were made by the author.

License

This project is licensed under the GNU General Public License v3.0, inherited from the original AtmChile R package.