Weather calculations
Mountain conditions estimator
Estimate how air temperature may change with elevation, then calculate wind chill from a wind speed you provide. The tool does not invent summit wind or replace a forecast.
How the temperature estimate works
The calculator applies the lapse rate you choose to the elevation difference. The default 6.5 °C per kilometre is a common environmental reference value, not a forecast for a particular mountain. Real temperature profiles vary with humidity, inversions, fronts, sun exposure and air-mass structure.
Why wind speed is a separate input
Valley wind cannot be converted reliably into summit wind with a simple formula. The tool therefore asks you to enter a wind speed from a mountain forecast or another source. It applies a standard wind-chill calculation only when the temperature and wind fall within the equation's usual range.
Use the estimate appropriately
Use this tool to understand sensitivity to elevation and wind. For a real trip, check current mountain forecasts, warnings, snow or avalanche information and local route conditions.