Shanghai experienced its biggest snowstorm of the past three years with falls of up to 13 millimeters.

The snow, which had continued for several days, started to intensify over Wednesday night and turned to heavy snow yesterday morning.

When residents woke yesterday they found a city covered in snow. Pedestrians found it difficult to walk in the slippery conditions and drivers had to take extra care to avoid accidents.

Snow and sleet will continue throughout the weekend but should easy off somewhat. Temperatures will range from just below zero to a high of 5 degrees over the next three days, the Shanghai Meteorological Bureau said yesterday.

Today will be snowy and cloudy while tomorrow the snow will turn to sleet and temperatures should rise to around 6 degrees, the bureau said.

Monday will be cloudy.

Yesterday's snow, which peaked in Qingpu District with a fall of 13 millimeters, brought back memories of 2008, when Shanghai had snow for five continuous days with a record fall 17 millimeters in Chongming County.

A blue snowstorm alert, the lightest of the four-level system, was issued by the bureau at 5am yesterday and was upgraded to yellow at 7:50am, indicating snowfall in excess of 6 millimeters and warning people of slippery conditions on roads.

A yellow road icing alert had been issued the previous evening. The alerts were lifted yesterday evening.

Zhang Ruiyi, a chief service officer with the bureau, said the continuing snow was caused by the interchange of the northern cold snap and southern warm air streams and was not a rare phenomenon.

"The city experienced such icy sleety and snowy weather in 2008, which was even heavier," she said.

Broken bones

But while many city residents were delighted to wake up in a winter wonderland yesterday morning, the snow also brought inconvenience and injury to others.

Even though thousands of city workers were dispatched to sweep the roads and sidewalks, hospitals reported an increase in patients admitted with broken bones, after falling on slippery surfaces.

The Shanghai No.6 People's Hospital, known for its orthopedics department, had received more than 70 patients with fractures sustained in falls by 5pm yesterday.

"Most patients arrived between 10am and 3pm," said hospital official Shen Yan. "They were injured while going out in the morning, when snow was still accumulating on the ground."

Officials from Shanghai Medical Emergency Center said ambulances responded to around 750 calls between yesterday morning and evening, about the same number as usual. However, more ambulances were dealing with people injured in falls or traffic accidents.

By evening, ambulances had gone to the aid of more than 60 people who slipped and around 50 who were involved in traffic accidents.

"We have been on alert since heavy snow was forecast and arranged for extra staff," said Guan Min, the center's spokesman.

"However, the demand has not been as heavy as we thought, since many people have avoided unnecessary journeys or are walking or driving more carefully."

The Shanghai Greenery and Public Sanitation Bureau sent 300 sweeping vehicles with 2,500 staff to clear all the major roads and remove falling branches from trees yesterday.

Vegetable prices have increased due to transport difficulties but are still lower than the same period last year, officials said yesterday.

Homeless people should take shelter in city aid centers during the current wintry weather, civil affairs officials advised. For despite the heavy snowfall many homeless people seem reluctant to seek help.

This year, up until yesterday, only 70 people had used the Shanghai Aiding Center in Putuo District, which can accommodate 1,000 people.

Meanwhile, city zoos and gardens say they have taken measures to ensure animals and plants that can't tolerate the cold are well protected.