IT will be the coldest Shanghai for early January in 20 years today with forecast of a high of minus 1 degree Celsius and alow of minus 7, the local weather bureau said.

The temperature in coastal districts will be minus 9 degrees in the morning. The lowest temperature — minus 5 — recorded during this period was in 2005.

An alert for cold weather was raised from yellow to orange at 7am yesterday. As of 6pm yesterday, two blue alerts for gales and cold wave issued on Wednesday, remain in place.

From tomorrow, the high temperatures will increase from 4 degrees to 8 degrees till Tuesday, with lows rising from minus 5 to minus 1. With the cold front leaving the city, air pollution will be back on Sunday, according to the environment bureau said.

Police increased the number of front-line officers by 30 percent to ensure traffic safety. They were guiding traffic and checking over 200 places such as steel bridges, ramps on overhead bridges and low-lying areas, for signs of frosts settling on them.

Greenery authorities prepared anti-freezing and anti-slip equipment such as sandbags and shovels. Housing management departments have been looking out for objects at danger of being blown down by strong winds. Over 2,000 maintenance staff are on standby for possible damage caused by the extreme weather.

China’s meteorological authority yesterday renewed a blue alert for a cold wave, with most parts of southern and northern China continuing to see drastic temperature drops and strong gales.

The mercury dipped to minus 19.6 degrees Celsius in south Beijing yesterday, marking the coldest morning in the Chinese capital since 1966.

On early Thursday morning, half of Beijing’s 20 national-level meteorological stations registered their lowest ever early-January temperatures, according to Lei Lei, chief forecaster of the Beijing meteorological station.