Abstract:Beijing 2008 Olympic Games will be held on 8-24 August. The extreme weather even ts in this period were analyzed by using the data of Beijing Observatory, Chaoya ng, Fengtai Shunyi Meteorological Stations from August 8-24（1971-2007), and Hai dian Meteorological Station（1975-2007）. The results show that the maximum high temperature (Tmax) at Beijing Observatory was 37.3℃ and the occurrence probabi lity of annual Tmax＞36.0℃ is 5%. The annual variation of Tmax obviously a ppears an ascending trend with the rate of 0.69℃/10a. It means that the tempera ture nowadays is in a relatively higher period, the annual mean days of Tmax≥33 ℃ at five stations is 2.8 with same increasing trend. The annual mean muggy days (Tm ax≥32.0℃ with the relative humidity ≥55%) is 4.7. The occurrence probability of daily rainfall (R≥25mm) at Beijing Observatory can reach to as high as 68%, the mean number of raining days (R≥25mm) for five stations is 1.1. The maximum daily precipitation intensity is 156.2mm/d. The mean day of thunderstorm is 3.7. These three factors mentioned above are in a lower-value periods. The mean day of strong wind (averaged wind speed ≥7m/s in 10 min) at five stations is 1.2 , and is also in a slower-speed period. The foggy day is 0.7. The day of low v isibility ≤2000m at Beijing Observatory goes down from 3.9(1990-1999) to 1.5(20 00-2007), also in a fewer-occurrence period.