By means of REOF, wavelet analysis and correlation analysis, the characteristics of summer high temperature were analyzed and the air-conditioner electricity consumption per square meter in dwelling hottses was calculated. Emphases were put on the temporal and spatial characteristics of high temperature. The results show that in the past 50 years there was no obvious change in accumulated high temperature generally, but there were some differences in different areas. The accumulated high temperature rose apparently in the southeastern Zhejiang and dropped somewhat in the northem and southwestern parts. After the 1980s, the differences of maximum temperature and the number of high temperature days between three high-temperature zones decreased apparently. Also the occurrences of extreme heat or cool events in summer in the past 50 years were analyzed. It is pointed out that air-conditioner electricity consumption in summer in Zhejiang was extraordinary and the air-conditioner electricity consumption in a hot summer was about 70 percent more than that in a cool summer on average.