Seasonal forecasts

action0.open_meteo.seasonal · Open-Meteo docs · SeasonalClient, preset to https://seasonal-api.open-meteo.com

GetV1Seasonal looks up to nine months ahead (CFSv2 and ECMWF seasonal systems). Like the Ensemble forecasts API it answers with per-member keys, so the variable series live in the models’ catch-all additional_properties field; daily=, weekly= and monthly= aggregations are available next to hourly=:

from action0.client.backends.requests import RequestsBackend
from action0.open_meteo.seasonal import (
    GetV1Seasonal,
    GetV1SeasonalDailyItem,
    SeasonalClient,
)

with RequestsBackend() as backend:
    client = SeasonalClient(backend)
    outlook = client.send(
        GetV1Seasonal(
            latitude="48.21",
            longitude="16.37",
            daily=[GetV1SeasonalDailyItem.TEMPERATURE_2M_MAX],
            forecast_days=45,
        )
    )

daily = outlook.daily
assert daily is not None and daily.additional_properties is not None
print(sorted(daily.additional_properties)[:2])
# ["temperature_2m_max_member01", "temperature_2m_max_member02"]

Notes

• Treat seasonal output statistically — the member spread over weeks and months carries the signal, single trajectories do not.

• Weekly/monthly aggregations keep the payload small for long horizons.