Based on the observation data of hourly temperature，daily maximum and minimum temperature，daily mean total cloud cover and rainfall from ten stations in Shaanxi Province from 2006 to 2010，a forecast method of hourly temperature was established by using linear regression method on the basis of forecast values of daily maximum and minimum temperature and observed values of hourly temperature，which was tested by comparing forecast values with observed values of hourly temperature at ten stations in Shaanxi Province in 2011． The results show that the forecasting ability of the forecast method of hourly temperature under sunny or lightly cloudy conditions was better than that under heavily cloudy or rainy conditions． The forecasting effect of the method was better between 2 o clock
and 18 o clock than that between 19 o clock and 1 o clock of the next day on sunny or lightly cloudy days，and was better between 1 o clock and 10 o clock than that at other time on heavily cloudy or rainy days． When the forecasted daily maximum and minimum temperature were comparatively accurate，the forecast accuracy of hourly temperature was more than 60% at Xi an station． The accuracy was 100% on sunny days and from 96% to 99% on lightly cloudy days between 14 o clock and 17 o clock． But the accuracy on heavily cloudy or rainy days was about 12% ～ 27% lower than that on sunny or lightly cloudy days between 11 o clock and 17 o clock． With the characteristic of diurnal variations of temperature change in different areas，seasons and sky conditions，the method can turn
the forecasted daily maximum and minimum temperature into forecast of hourly temperature well． To some extent the forecast method of hourly temperature has application and extension values．