The presence of a diurnal variation in meteor activity is well established. The sporadic meteor count rates are higher on the local dawn side and lower on the local dusk side. This phenomenon is caused by the Earth's orbital motion and rotation. Meteor radar measurements have been compared from Esrange, Kiruna, Sweden, at 68 degrees N, from Juliusruh, Germany, at 55 degrees N, and from Ascension Island, at 8 degrees S, to investigate how the diurnal variation depends on season at different latitudes. Data have been used from vernal and autumnal equinoxes and summer and winter solstices to locate the largest seasonal differences.