The temperature distribution in an electric coil winding is determined by solving the differential equations which apply to the system approximately. The maximum and average temperature rises are given for several types of windings. A distinction is made between small and large temperature rise; the treatment of the former neglects local changes in resistivity and thermal conductivity caused by the increase in temperature. A correction factor is computed to obtain the actual temperature rise from the much simpler calculations for the maximum temperature rise which would occur if the resistance were independent of temperature. It is found that non‐uniform windings, wound of several different wire sizes to minimize the resistance, exhibit the same temperature rise characteristics as conventional uniform windings of zero curvature.