Strong winds swept through Beijing yesterday and cleared the air of smog that had blanketed it on Saturday, only to bring sand.
Heavy gusts picked up around noon, mixed with local dust and sand from Inner Mongolia , which was hit by a strong sandstorm yesterday. As well as reducing visibility and stirring up debris such as plastic bags, the winds were strong enough in Beijing for some people reporting that their windows rattled loudly.
The capital's Environmental Monitoring Centre tracked the sand to the Inner Mongolia storm that blew in via Hebei .
Air quality took a noticeable hit. The centre said the level of PM10 pollutants - those with a diameter of less than 10 microns - increased sharply around noon and surpassed 500 micrograms per cubic metres.
"Pay attention to protection, shut the doors and windows, and limit outdoor activities," the centre advised. The air-quality index provided by the US embassy peaked around noon before improving late in the afternoon.
Meteorologists' classification which warned of "flying sand" instead of a "sandstorm", was due to differences in visibility, but many Beijingers still called it a sandstorm, and said they were caught off guard.
"The sandstorm hit my face, and it hurt," wrote one microblogger going by the name Mufei, who added that "the most appropriate forecast could have been 'don't go out'. Will this continue?"
"What terrible weather! Strong winds with sand and fluffy poplar tree seeds. I can hardly breathe," wrote another blogger.
Meanwhile, the National Meteorological Centre issued a blue alert warning for rainstorms - the lowest alert - for southern provinces. The centre warned the provinces to take precautions against urban waterlogging, torrential floods and landslides.
Guangdong and Guangxi were expected to get between 100 and 130mm of rain within 24 hours, the centre said.
Continuous rains since Thursday have claimed a life while affecting nearly 200,000 people in Guangxi.
Rain has battered 14 counties and left more than 12,100 people displaced in the province.