Hangzhou meteorologists forecasted that tropical storm Fung-Wong would bring heavy rains and strong gales to the city today after making landfall in coastal areas in Zhejiang Province.
The city's weather station forecasted level 6 to 8 gales today, while the National Meteorological Center maintained a yellow alert.
China has a four-tier color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.
The highest temperature in downtown area will hover between 24 and 27 degrees Celsius before Wednesday.
The heavy rain will weaken tomorrow and die down by Wednesday afternoon, they said.
From Thursday, cloudy and overcast weather will continue to the weekend with the high rising to 30 degrees on Sunday, according to the city's forecasters.
The city's flood prevention authorities are advising relevant departments to check on construction sites, cranes, trees, advertising boards, signboards and glass walls. Floodways are being drained in preparation for possible flooding.
Preparations are also being made for the evacuation of coastal area residents and ships are being advised to stay in harbor.
Police officers have been put on standby and will work with road authorities to monitor underpasses, while construction and traffic authorities are checking underground structures, including Metro stations, garages and squares.
Air China's flight to Taipei Airport from Xiaoshan International Airport has been cancelled for yesterday and today.