The best trails today

Every 3 hours from Open-Meteo forecast data. Soil moisture and temperature use modelled data at the trail elevation for each location. Historical data from previous days feeds the drying trajectory calculation.

Two layers combined: Trail Condition (45% weight) covers soil moisture, freeze-thaw state, and drying trajectory. Weather Window (55%) finds the best contiguous 4-hour riding block and scores temperature, precipitation, thunderstorms, wind, visibility, and sky. The composite has ceiling caps so neither great trails nor great weather alone can produce an inflated score.

Mountain bike trails typically sit at valley and mid-mountain elevation, not at the ski-area summit. Each location fetches weather data at its trail-level elevation (elevation_base_m) for accurate soil and temperature readings.

A score below 20/100 on the shared platform bands. There are no hard storm or cold stops: snow cover, heavy rain, severe gusts and saturated ground each multiply the score down through their own factors, and days that fail several at once land in this band. Lightning risk is shown as a separate safety flag and never moves the score.

The ideal soil moisture level (roughly 0.10-0.14 m³/m³) where trails have enough moisture for grip and tack but no standing water or mud. Too dry means loose and dusty; too wet means ruts and erosion. The scoring model peaks at this sweet spot.

Yes, the same mountain locations. Great ski days and great MTB days are seasonal opposites: skiers want deep snow and cold; riders want dry trails and warm weather.