Tiananmen Square
Cyclists ride through smog in Beijing's Tiananmen Square. Sun jun Imaginechina via AP Images

Beijing just declared a “red alert” as smog continued looming over China’s capital city. The BBC reports that the alert will close schools, stop all outdoor construction, close factories and restrict the number of cars on the road for the next few days. The smog is back, after a brief reprieve of blue skies interrupted the city’s frequent haze.

Smog levels are actually lower now than they were last week when particulate matter in the air reached 35 times the safe limit. Then colder weather briefly whisked the smog away, but now it’s returned.

The Chinese government has been notoriously reluctant to issue the highest level of alert, a move that can dramatically slow down the city’s commerce, transportation and other services. Other cities in China have issued red alerts in the past.

The alert will be in place until Thursday, when better weather conditions (cold and wind) are expected to blow the smog away.

The initiative to close factories, halt construction and get cars off the road will also likely help alleviate the pollution. Similar measures put in place for major conferences, like the Asia-Pacific Economic Cooperation (APEC) summit where the city wants to put its best sky forward have had excellent results and blue skies.