Cragcast checks the weather forecast for crags near Seattle and rates climbing conditions with traffic light colors: green for good, yellow for marginal, and red for poor conditions.

How we rate conditions

We rate temperature, sun exposure, humidity (using dew point), wind, and available air quality together for each hour. Morning covers 7am–1pm and afternoon covers 1pm–7pm, in local time.

A window is good with at least four consecutive good hours and no poor hours. It is poor with at least four poor hours, consecutive or otherwise. Other combinations are marginal.

We use seven days of hourly rain history to estimate surface wetness and, at crags known to seep, seepage potential. Each rain hour adds moisture; temperature, dew point, wind, sunlight, aspect, and rock type affect surface drying. Seepage fades more slowly. The estimates start dry seven days back and continue through the seven-day forecast. These are uncalibrated estimates, not observations or precise drying times. Humidity alone does not mean wet rock. The displayed 24h and 72h rain totals are context, not color thresholds. Forecast rain can worsen the whole window's rating. The worse half sets the day's color.

An area is green when most crags are good, red when most are poor and none are good, and yellow otherwise.

The rating system is still being refined. We'll keep adjusting it to better reflect conditions at the crag.

How to support

Cragcast is free. To support it, please take care of the crags it covers: pack out any trash you find, don't top-rope directly on fixed gear, and support local climbing organizations. Weather forecasts come from Open-Meteo, which also provides air quality forecasts using data from the Copernicus Atmosphere Monitoring Service (CAMS). Please support them too.

Get in touch

Questions, corrections, or crag suggestions? Email anton.evseev@proton.me.

Data license

Open-Meteo forecast data is licensed under CC BY 4.0. Cragcast uses this data to calculate climbing condition ratings.