With the help of cold air that has blanketed northern China and humidity brought by an east wind, the command centre blasted 186 sticks of silver iodide into clouds above the city between 8pm on Saturday and 2pm yesterday to help precipitation, a command centre official said.

'Although it was too early for snowfall, the conditions were suitable, and we weren't going to ignore any opportunity [to induce rain and snow] now, because we are facing very severe drought,' said the official, who refused to be named. The chemicals were used first to induce rain on Saturday and then snow yesterday, he said, 'but the 16 million cubic metres of water is far from enough to mitigate the drought in Beijing'.

Artificially altering the weather is practised on the mainland for various purposes - from mitigating drought to ensuring good weather for the grand National Day parade this year. In February, Beijing authorities induced snowfall by firing 500 sticks of silver iodide into clouds in a bid to ease another severe drought.

Yesterday's snowfall, which began around midnight and ended in the afternoon, was so heavy that some tree branches were fractured by the weight and 40 snowploughs were deployed to clean the streets.

'This is probably the biggest snowfall I've ever seen since I moved to Beijing 11 years ago,' public relations specialist Li Wei said.

At least 200 flights were delayed at Beijing Capital International Airport in the morning as some runways were closed for snow removal, the airport authority said.

Only 57 of 257 scheduled flights took off in the morning, it said. This prompted complaints from some stranded passengers that the airport had failed to provide updates.

Road traffic in the city appeared less congested as well, as many people chose to spend the chilly weekend indoors. Xinhua reported that traffic around suburban tourist attractions such as Fragrant Hills was quiet. No road closures were reported.

Yesterday's snowfall was the earliest in the autumn since 1987, which saw one on October 31, the Mirror reported yesterday. It was also the third-earliest on record. The earliest was on October 26, 1960.

Special contingency plans will be initiated this morning in the face of possible traffic congestion as people begin the working week. Today's forecast calls for winds to swing around to the west and become stronger, with predicted lows of about minus 4 degrees Celsius, the Beijing Meteorological Bureau said.

Frozen out

The number of flights delayed at Beijing Capital International Airport because of the snowfall: 200