This paper introduces a human climate classification of Australia based on thermal stress. The classification derives from a new comprehensive scheme in which theoretical and semi-empirical expressions are used for each individual heat exchange term in the steady-state energy balance of a naked, average person, standing at rest and facing the sun. For 0900 and 1500 LST in mid-January and mid-July, the thermal stress on such a reference individual is calculated from air temperature, vapor pressure, global radiation and wind speed for some 144 locations across Australia. Maps are discussed which portray in meaningful physical units the distribution of cold stress and heat stress. Abstract This paper introduces a human climate classification of Australia based on thermal stress. The classification derives from a new comprehensive scheme in which theoretical and semi-empirical expressions are used for each individual heat exchange term in the steady-state energy balance of a naked, average person, standing at rest and facing the sun. For 0900 and 1500 LST in mid-January and mid-July, the thermal stress on such a reference individual is calculated from air temperature, vapor pressure, global radiation and wind speed for some 144 locations across Australia. Maps are discussed which portray in meaningful physical units the distribution of cold stress and heat stress.