Mean relative humidity between ca. 600 and 3000m above the ground level This map presents the average relative humidity between about 600 and 3000m above the ground - equivalent to the atmospheric layer between 2000 and 10000ft. Although this map is by far not as important as the 'RH 700 hPa' or the 'RH 925 hPa', it gives some hints on cloud formation especially between these two pressure altitudes.