A summary of the linear trends estimated from the USU Rayleigh Lidar (41.74º N, 118ºW) temperature data set. The data set covers a time span from September, 1993 to August, 2003 and an altitude range of 45 to 80 km. The data set includes 584 data points at 45 km to 580 data points at 80 km. Cooling trend profiles are calculated and compared to results from other researchers. Collinearity and bias are also considered as issues that could affect the regression results. Also considered is the possibility that the Mt. Pinatubo eruption has influenced temperature trend estimates. This is important because the Pinatubo-related mesosphere temperature response occurred about the time the USU lidar came on line, which could be affecting our trend estimates. A visual comparison of the annual and semiannual oscillations are also presented.