The lapse rate from 126 to 175 km is +10.0°C km -1; temperature at 175 km is 539.7°C (molecular-scale temperatures). 1  The U.S. Extension to the ICAO Standard Atmosphere is essentially a recomputation of the above data from the surface to 300 km.2  See air.he lapse rate from 126 to 175 km is +10.0°C km -1; temperature at 175 km is 539.7°C (molecular-scale temperatures). 1  The U.S. Extension to the ICAO Standard Atmosphere is essentially a recomputation of the above data from the surface to 300 km. 2  See air.