How It Works

We turn high-resolution weather data into real‑world climbing conditions.

Rock Temperature (Trock)

We estimate the wall’s surface temperature since friction depends on the rock itself. We factor in:

  • Sun on the wall: time of day + your wall’s aspect and tilt.
  • Shade: face/terrain shading when the sun is behind the wall.
  • Sunlight strength: shortwave radiation (hourly).
  • Wind cooling: stronger when wind hits the wall head‑on.
  • Sky cooling: clear skies cool the wall more than cloudy skies (cloud cover).
  • Surface traits: rock tone/emissivity and snow on ground (higher reflectivity).
  • Thermal inertia: rock warms/cools gradually, not instantly, hour‑to‑hour.

Grease Factor

Slickness increases near dewpoint and at high humidity; recent rain and sun/wind matter.

  • Dew risk: based on dewpoint depression from temperature & humidity.
  • Surface vs air: we prefer the rock surface temperature for dew‑likelihood.
  • Humidity adsorption: some rocks feel slick at high humidity even without dew.
  • Sun & breeze relief: daylight and wind can reduce surface moisture/grease risk.
  • Recent rain memory: MRMS precipitation (24h & 7‑day) and seepage behavior.

Wind At The Wall

We estimate the wind that actually hits the wall you’re on.

  • Direction vs wall: more exposure when wind points into the wall; less cross/behind.
  • Canyon channeling: optional site/canyon axis boosts aligned winds, damps cross‑axis.
  • Diurnal flows: upslope day / downslope night in valleys when ambient is calm.

Data We Use

  • Open‑Meteo: hourly temp, humidity, wind, cloud, sun strength (shortwave), rain/snow, snow depth.
  • NOAA MRMS: high‑resolution rainfall (recent 24h and 7‑day) for drying & seepage memory.
  • Your wall: aspect & tilt from the UI, plus crag location & time zone.
  • Solar position: sun angle at your crag each hour.

What You Can Control

Use the toggles on each crag to preview different setups.

  • Wall aspect (N/NE/…/W) and tilt (slab/vertical/overhang).
  • Site (valley/ridge/…/canyon) and canyon axis (when relevant).
  • Rock type (if we got it wrong!).
  • Shaded (when trees or surroundings block direct sun).
  • Ideal temperature (if you like it a little warmer or cooler than the default).

Let me know what you think!

Have feedback from your local crag? I’d love to hear your thoughts!

Send it my way atcragreport@gmail.com