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Through analyzing the data of lowtemperature and overcast weather processes from November to next March from 1998 to 2007, it is found that the 500hPa circulation patterns during continual overcast weather (snow, fog) in Hebei Province can be divided into three types on the Eurasian region from November to next March for each year: cold vortex, trough, and highpressure. As a example, the disasterinducing environment and the vegetable growing state in greenhouses during the process of lowtemperature and overcast weather in January 2001 are analyzed.