Live - 4 km

Switzerland - Soaring Weather API

High-resolution WRF forecasts across the entire Swiss Alps. Interlaken, Verbier, Grindelwald, Fiesch, Engelberg, Crans-Montana, and every coordinate in between - thermal strength, MSL cloudbase, soaring height, convergence, served as JSON four times a day.

Model specifications

ModelWRF (Weather Research & Forecasting)
Resolution4 km
Domainthe Swiss Alps and surrounding terrain
Updates4× daily - 00z, 06z, 12z, 18z UTC
Vertical levels40+ pressure levels from surface to 50 hPa
InitialisationNOAA GFS global model
StatusLive

What you get for Switzerland coverage

All fields available now at 4 km.

Thermal Strength

wstar_ms - thermal updraft velocity in m/s

Soaring Height

hglider_agl_m + hglider_msl_m - usable thermalling height

Cloudbase

cloudbase_agl_ft + cloudbase_msl_m, Cu potential, OD risk

Wind

surface_wind_* plus wind_925_*, wind_850_*, wind_800_*, wind_700_*

Trigger Temperature

thermal_trigger_temp_c - surface temperature at which thermals fire

Day Rating

day_rating - poor, marginal, fair, good, excellent

Corridor Sampling

Weather along a route - time-aware available

Sounding Profile

Full vertical profile - temp, dewpoint, wind

Query Switzerland forecasts in seconds

Pass region, resolution, and any covered coordinate - the API resolves the nearest model grid point and returns the forecast.

Request

curl "https://api.convek.dev/v1/site?region=ch&resolution=4km&lat=46.1&lon=7.23&time=13:00" \
-H "Authorization: Bearer cvk_live_your_key_here"

Response

{
"valid_date": "2026-05-09",
"valid_time": "13:00",
"rasp_model": "ch/4km",
"site": {
"wstar_ms": 2.1,
"hglider_agl_m": 963,
"cloudbase_agl_ft": 3653,
"cloudbase_msl_m": 2684,
"surface_wind_speed_ms": 3.3,
"surface_wind_dir_deg": 22,
"day_rating": "fair"
}
}

About soaring weather in Switzerland

Switzerland has the densest soaring population per square kilometre in Europe and an absurdly varied terrain mix. Lake-edge sites like Niederhorn, classic Alpine launches at Interlaken and Grindelwald, the high Valais bowls above Fiesch and Verbier, the Bernese Oberland 4000ers, the Mythen and Engelberg ridges - all in one box.

Swiss thermals punish any model coarser than about 5 km. Thermals trigger on south-facing rock faces hours before they fire on the valley floor. Cloudbase climbs through 4000 m on the best days, then collapses 800 m in twenty minutes when the föhn breaks. The wind picture switches between valley-driven and synoptic flow through the afternoon. Most of that resolves at 4 km. Almost none of it resolves at 13 km.

MSL cloudbase is the field Alpine pilots end up using most. Launch altitudes vary by 2000 m between Swiss sites, so the AGL number on its own can be misleading when planning a transition. Convek serves both AGL and MSL. The day-window calculations and sounding labels use Europe/Zurich.

Switzerland coordinate range

The live ch/4km region covers the Swiss Alps and surrounding terrain. Valid coordinates for queries sit inside this bounding box:

Latitude

45.3° N - 48.3° N

Longitude

5.2° E - 11.2° E

Requests outside this domain return 400 Bad Request with a message explaining the coordinates are outside ch coverage. See the coverage overview for other regions.

Start querying Switzerland soaring data now.

Free tier - 25 queries/day. No credit card required.