In order to provide reference for the forecast of disastrous weathers, based on daily sounding data at 07:00 (Beijing time, after the same) and 19:00 from May to October at four stations of Dunhuang, Jiuquan, Zhangye and Minqin over Hexi Corridor during 2006-2015, the variation characteristics of 0℃ isotherm height as well as its relationships with dry-wet, precipitation and disastrous weather were analyzed. The 0℃ isotherm height is most closely related to the daily extreme temperature, 0 cm minimum ground temperature; the higher the extreme air temperature and ground temperature is, the higher the 0℃ isotherm height is, and the best correlation is between the 0℃ isotherm height and 0 cm minimum ground temperature at 19:00, the coefficient of which is greater than 0.95. The value of temperature and dew difference (T-Td) is inversely correlated with daily precipitation, daily minimum air temperature and 0 cm minimum ground temperature, but is positively correlated with the daily temperature range, and the maximum correlation coefficient is greater than 0.7. The 0℃ isotherm height over Hexi Corridor was 3300~5000 m, the atmospheric pressure was 680~560 hPa, the T-Td was between 10~17℃, the height was low and wet in morning, but which was opposite at night. In dry and wet weather contrast, dry weather 0℃ isotherm height was high, obvious morning-evening variation and higher at 19:00, while the morning-evening variation of T-Td was obvious and more humid at 07:00 in wet weather. When precipitation occurred, the 0℃ isotherm height was 3000~4800 m, the atmospheric pressure was 750~570 hPa, T-Td < 8℃, and T-Td < 6℃ at 07:00; in day-night variation, low 0℃ isotherm height occurred at 07:00 in nighttime rainfall, while which occurred at 19:00 in daytime precipitation. In different precipitation levels, the maximum values of T-Td from light rain, to moderate rain and heavy rain were 2℃, 5℃ and 9℃, respectively. Thunderstorm 0℃ isotherm height was 3600~4900 m, the pressure was 660~560 hPa, T-Td ≤ 7℃. In gale and sand-dust weather, 0℃ isotherm pressure was 700~540 hPa, sandstorm 0℃ isotherm height at 07:00 from July to September was higher 300~500 m than that of gale and sand-dust, which was above 5000 m from July to August. When sandstorm occurred, it was dry at 07:00 but wet at 19:00 when T-Td < 5℃, so sandstorm in flood season often occurred in the precipitation afternoon. In daily maximum temperature ≥ 35℃ high temperature weather, 0℃ isotherm height was 4600~5300 m, the pressure was 570~530 hPa, T-Td ≥ 13℃.