Dry Adiabatic Lapse Rate

The dry adiabatic lapse rate is the typical cooling rate of an unsaturated air parcel as it rises through the atmosphere, about 9.8 °C for every 1 km increase in altitude. It happens because rising air moves into lower pressure, expands, and uses its internal energy to do that expansion, which lowers its temperature even though no heat is lost to the surroundings. The word "dry" means the air parcel is not saturated, so condensation and latent heat are not part of the calculation.

Use this when estimating the temperature change of a rising or sinking parcel of unsaturated air in meteorology, mountain weather, or atmospheric stability problems. It is especially useful for questions involving uplift over hills, convection, or comparing air temperature at different heights.

• Using this rate for saturated air, where condensation changes the cooling rate
• Forgetting to convert altitude change into kilometres before multiplying
• Applying the rate to environmental air temperature instead of a moving air parcel