The optical and meteorological properties of smoke-dominated haze at the Southern Great Plains Central Facility of the Atmospheric Radiation Measurement (ARM) Program from 1997 to 2001 are presented. Aerosol optical properties for smoke-dominated haze vary with season at the ARM site, with an inter-seasonal mean single scattering albedo, ¿ngstr¿m exponent, hemispheric backscatter fraction and hygroscopic growth factor of 0.91 ¿ 0.03, 2.0 ¿ 0.1, 0.14 ¿ 0.02 and 1.6 ¿ 0.2, respectively. In addition, the local seasonal direct radiative forcing for smoke haze ranges from -0.25 to -3.14 Wm-2. Relative to smoke-free periods, months with enhanced smoke are characterised by reduced cloud cover, increased shortwave radiation, lower liquid water path and precipitation.