Trying to keep warm on a street in Huangpu District on Tuesday.

Four yellow alerts for cold, road icing, a cold wave and gales, were issued by the city’s weather bureau on Tuesday.

It was the first cold alert released at 5pm since it was added to the local alert list in June last year.

It indicates that the low temperature will decline to minus 5 degrees Celsius in 24 hours. And it in some places, especially the suburban areas, will reach minus 7 degrees.

The alert for road icing was released at 9pm, indicating that the icy road will be seen in 24 hours. People should pay attention to the traffic accident, avoid riding bikes and don’t fall. And the other two alerts were also issued at 11am.

The maximum temperature will plunge from 16.6 degrees Celsius on Tuesday to minus 1 degrees on Wednesday, with increasingly strong winds.

Wang Rongjiang / SHINE

A bike is blown over by the strong wind in Xuhui District on Tuesday.

Wang Rongjiang / SHINE

People help a man pick up his goods after his bike was blown over in the wind.

Local coastal areas have been pounded with winds of more than 100 kilometers per hour, capable of uprooting trees and damaging buildings. People in urban districts also sufferedgales of 74 kilometers per hour.

Moderate rain began on Tuesday afternoon and sleet and snow are expected on Tuesday night and early Wednesday morning.

Snow has fallen in some districts, including Jiading, Chongming and Jinshan, around 7:30pm.

People are being encouraged to close windows, stay inside and keep warm. Those who must go outside should be alert for falling objects such as window glass and advertising boards.

Jiang Xiaowei / SHINE

The snow is seen near the Shanghainan Railway Station in Xuhui District on Tuesday night.

Jin Jiamin

The snow falls on a person's woolen hat in Jiading District on Tuesday.

The city’s bus company has issued emergency plans to cope with the chill, including checking antifreeze to ensure buses can run normallyat low temperatures.

As a large proportion of city’s buses are electric, technicians have also examined the condition of batteries and charging devices.

Several routes, including Line 43, have prepared warm beverages such as black-sugared ginger tea for crew and passengers.

Safety rules are being reiterated for drivers including speed limits and safe distances. Potential icy roads have also been marked out for drivers.

Anti-freezing and anti-slip tools such as salt bags, sandbags, mats and shovels are provided to ensure the safety of vehicles.

Hu Min / SHINE

Two workers take measures to protect trees at Zhabei Park.

At Zhabei Park in Jing'an District, more than 50 palm trees and sago cycas were wrapped in fabric on Tuesday.

"Straw was commonly used in the past to protect trees," said Jiang Haibin, director of the park.

"However, non-woven fabric is easier to use and it is light, which will not affect the bark," said Jiang.

Ferns have been covered by a 200-square-meter nylon mesh.

"Ferns are more vulnerable to frost and they will soon wither without protection," said Jiang.

At Gongqing Forest Park in Yangpu District, white lacquer has been applied to peach trees and Chinese flowering crabapple trees as a precaution and to prevent pests.

Hu Min / SHINE

Sanitation workers in Huangpu District prepare ahead of the cold wave.

Sanitation workers on Nanjing Rd E. have prepared snow-melting agents and shovels.

"We have prepared enough stock and the slopes on bridges along the Suzhou Creek are slippery due to thefreeze, posing hazards, said Li Jiayu, a sanitation worker.

"We need to check the road conditions frequently to clear ice and snow and employ sacks to ensure the safety of pedestrians," he said.

The sun will be back during the week. Although the forecast calls for temperatures above freezing on Thursday afternoon, the low on Thursday night could hit minus 6 degrees.

Friday will bring warmer temperatures, with the high on Sunday forecast to be 11 degrees.