The location of the clouds is predicted based upon the temperature at which vapor will condense into droplets. The temperature at which the condensation occurs, according to the temperature profile shown in the figure by the black line, is where the clouds ought to be.

The diagram shows that the temperature in the troposphere goes from about -300 degrees (100 K) to about +80 degrees (300 K).

The first clouddeck, made of ammonia clouds is found at about 100 km below the tropopause, where the temperature becomes about 150 K. The second clouddeck, made of ammonium hydrosulfide clouds is found at about 170 km below the tropopause, where the temperature becomes about 200 K. And the third clouddeck, made of water clouds is found at about 130 km below the tropopause, where the temperature becomes about 270 K (freezing temperature for water).