Starting at 2:30 p.m. yesterday, the fog lasted for more than an hour. In downtown, visibility was reduced to 500 meters, while it reached 1 kilometer in suburban areas, according to the Shanghai Meteorological Bureau.

"Foggy weather is common in the present season, which usually results from high humidity, weak winds and low pressure," said Dai Xinfu, the city's chief meteorologist.

According to Dai, showers are likely to prevail through the weekend. Today's high should be 12 degrees Celsius, while the low is expected to be 8 degrees.

The fog didn't trouble the city's Hongqiao Airport which is located in the southwestern Shanghai.

"There's no fog here. All the flights are operating under their original schedule," said Jiang Yao, a spokeswoman for the Air Traffic Management Bureau.

At the city's busier Pudong International Airport, controllers said light fog hit the airport but "didn't affect the departure and arrival of planes."

Ferries running on the Huangpu River didn't suspend services yesterday, according to Shanghai Ferry Ship Service Company.

No problems were announced on highways linking Shanghai to other parts of the country or the city's elevated roads.

More fog is expected to blanket the city during the week due to an active wet air mass from southwestern China, according to local meteorologists.

(eastday.com February 27, 2003)