The first incoherent scatter radar local time/seasonal/solar cycle averages of F region electron, ion, and neutral temperatures for Asian longitudes are presented. These measurements were made with the four-pulse experiment by the middle and upper atmosphere (MU) radar in Japan over the period August 1986 to April 1990. The neutral temperature and density results are compared with MSIS-86 model predictions. We divide our data into low and high solar activity levels, four seasons, and 24 one-hour times bins. While the seasonal and solar activity behavior of the ionospheric density, and of the anticorrelation of the electron temperature with this density, shows many aspects in common with those at other locations, a few particular differences are evident. At low solar activity the height of the F layer varies from 240 km during the day to 320 km at night, regardless of season. At high solar activity the maximum density of the F layer varies little with season. These facts seem to indicate little seasonal change in F region neutral atmospheric composition at this geographic location. At solar maximum the F layer is established at a higher altitude than at low solar activity, and the summer F layer in particular is formed at such a high altitude that its decay at night is very slow, its diurnal variation is hence weak, and the density remains so high at sunrise that little sunrise effect in the electron temperature is produced. The neutral temperatures in the F region have the same basic diurnal pattern as does the MSIS-1986 model temperatures, but the radar temperatures are consistently lower by an amount ranging up to 160 K for summer conditions at high solar activity. The measured and model temperatures are closest in the autumn and winter. The neutral density results are of low quality and do not provide any evidence of need to modify the MSIS model densities. ¿American Geophysical Union 1991