The subauroral nightside electron temperature peak is one of the phenomena showing the response of the subauroral ionosphere to the influx of magnetic storm energy in the vicinity of the plasmapause. A statistical study of the seasonal variations of the subauroral electron temperature enhancement was undertaken using data from the Langmuir probe experiment on the DE 2 satellite throughout most of the mission (1981--1982). In the winter hemisphere the nighttime background electron temperature is the highest and the magnitude of the peak Te responds most weakly to the geomagnetic activity. This behavior can be explained by seasonal trends in the nighttime downward heat flux due to conjugate photoelectrons. Moreover, model results indicate that a factor of ~3 increase in heat inflow during equinox relative to solstice is required to raise the electron temperature to a given level. This is a consequence of the higher electron densities at the Te peak equinox. The Te peak occurs on field lines which thread the outer plasmasphere in the vicinity of the plasmapause and thus can be used as a tracer of the plasmapause position. Correlating the position of the Te peak with Kp (the highest value of 3-hour Kp in the preceding 12 hours) indicates a trend toward a more expanded quiet time plasmasphere and one which is more easily compressed by magnetic storms at equinox than during the solstice period. ¿ American Geophysical Union 1991