The climate background for high temperature is defined on the basis of the statistic analysis of the distribution characteristics, times, and intensity of high temperature weather (greater than 35 ℃) in Changzhi from June to August, 1977 to 2004. By analyzing the circulation at 500 hPa, four kinds of favorable circulation patterns are found: two troughs and one ridge, zonal circulation pattern, continental warm high, and subtropical high. The relation between weather factors (such as wind, clouds, precipitation, etc.) and high temperature weather is analyzed. A comprehensive model for forecasting high temperature is thus devised by selecting index stations of high temperature at 850 hPa and analyzing numerical forecast products, which plays an active role in the operational meteorological service.