An original method la devised here and instrumentated for the measurement of heat transfer from precipitation particles (particularly liquid drops) to the atmosphere when the particles are falling at their terminal velocities. The results of the measurements made by this system are compared to what simple theory predicts. A qualitative discussion is made of the reasons for the discrepancy. The shortcomings of the general measurement method are discussed and suggestions are made for extension and improvement of the system. Heat transfer data for various drop sizes at terminal velocity and for an artificial snow-flake are presented.