The temperature distribution was investigated in the combustor of a 165-MWth, atmospheric-pressure circulating fluidized-bed (CFB) boiler located in Orebro, Sweden. The temperature was measured with a bare 1-mm Chromel-Alumel thermocouple at different heights and at different distances from the fin surface of the membrane wall. The investigation covers two fuels (coal and peal) at boiler loads of 85 and 165 MWth, respectively. The results show that the thermal boundary-layer thickness increases with increasing height and with decreasing superficial gas velocity. The fuel has a significant influence in the lower and upper parts of the combustion chamber. In addition, the results from this boiler are compared with other available temperature distribution data in the literature.