Skip to content

Citizen weather stations

weather.cwop reads Personal Weather Station reports from the Citizen Weather Observer Program. Use these rows as separately sourced weather inputs, never as an official settlement value.

Install the Python extra

Section titled “Install the Python extra”
Terminal window
pip install "mostlyrightmd-weather[cwop]"

CWOP is currently a Python-only surface. Live reports arrive through the APRS-IS TCP network; there is no official REST archive to query later.

Find stations near an official station

Section titled “Find stations near an official station”
from mostlyright.weather import cwop


stations = cwop.nearby(
    "KNYC",
    radius_km=25,
    listen_seconds=60,
)


for station in stations:
    print(
        station.id,
        station.distance_km,
        station.last_temp_f,
        station.qc_status,
    )

Use scan(latitude, longitude) when you already have coordinates.

Collect current reports

Section titled “Collect current reports”
from mostlyright.weather import cwop


frame = cwop.snapshot(
    "CW0875",
    duration_seconds=120,
    quality_control=True,
    persist=True,
)


print(frame[[
    "station_id",
    "observed_at",
    "knowledge_time",
    "temp_f",
    "qc_score",
    "qc_status",
    "source",
]])

snapshot() waits for a fixed collection window and returns a schema.cwop.v1 frame. With persist=True, it also writes the collected rows to the local monthly cache.

Use latest() for one blocking observation or stream() for an asynchronous sequence:

async for observation in cwop.stream("CW0875"):
    print(
        observation.observed_at,
        observation.temp_f,
        observation.qc_status,
    )

Replay only what you collected

Section titled “Replay only what you collected”
from datetime import date
from mostlyright.weather import cwop


history = cwop.history(
    "CW0875",
    date(2026, 1, 1),
    date(2026, 6, 30),
    qc_status="clean",
)

The APRS-IS stream cannot backfill dates before your collector started. history() reads only rows previously written by snapshot(persist=True) or persist_observations().

Live rows use source="cwop.live". Replayed rows use source="cwop.cache".

Keep CWOP separate from official observations

Section titled “Keep CWOP separate from official observations”

Personal stations can be indoors, mounted over hot roofs, or poorly calibrated. Mostly Right keeps CWOP out of the official observation merge and out of weather-market settlement labels.

The QC pipeline scores range, temporal consistency, indoor behavior, nearby official stations, solar bias, and reporting reliability. Keep qc_status visible when you join these rows into your own analysis.

Errors and limits

Section titled “Errors and limits”
  • NoCWOPDataError is raised when no station or report arrives in the requested window.
  • Live calls may wait for the configured listen or timeout period.
  • No browser client is provided because APRS-IS requires a TCP connection.
  • Move CWOP state with MOSTLYRIGHT_CWOP_DIR; move the shared cache root with MOSTLYRIGHT_CACHE_DIR.

See also

Section titled “See also”