Combination photo taken on Aug. 30, 2016 (upper) and Dec. 20, 2016 shows a sharp contrast of air quality in an ancient town of Taierzhuang, east China's Shandong Province. Heavy smog lingers in Beijing, Tianjin and provinces of Hebei, Henan and Shandong on Tuesday.
Fresh air has become a luxury for many Chinese.
A large part of northern China has been wrapped in heavy smog since last weekend, 23 cities have activated red alerts, the highest in a four-tier warning system for severe weather.
The Beijing environmental monitoring center said Tuesday that the worst pollution is yet to come, lasting from Tuesday evening to Wednesday. The smog will disperse from Wednesday evening to Thursday, when a northern wind is expected.
At least nine expressways were closed in Beijing on Tuesday morning, according to the municipal traffic management bureau.
A total of 273 flights were canceled as of 2 p.m. Tuesday, Beijing Capital International Airport said on its official Weibo account.
Kindergartens and primary schools in Beijing, Tianjin, Xi'an and Zhengzhou have been suspended, with high schools also suspended in some places.
Beijing-based magazine "DUKU" on Monday sent an apology letter to subscribers, saying that their last edition of 2016 would not reach readers until after the New Year due to a temporary closure of the printing factory under the red alert.
Many ready-to-eat products are absent from shelves in convenience stores in Beijing because delivery trucks are banned in the city proper.
According to a circular released by Langfang City, which neighbors Beijing, all restaurants and breakfast stalls in county seats without cooking fume processing equipment are ordered to halt operations from Dec. 17 to 31. It also requires suspension of all construction projects in the city from December until mid-March.
"I can't even find a fried dough stick stall for breakfast," complained a resident in the city's Wen'an County, who did not give his name.
The air has forced many to escape.
A tourist surnamed Li flew to southern China's Hainan province with her two-year-old granddaughter to flee the smoggy air in Lanzhou, capital of northwest China's Gansu Province.
"We feel much better here than in Lanzhou," she said.
Blue skies have become a draw for cities with clear air. Li and her friends are planning to purchase houses in Hainan to escape to during winters, when smog is most frequent.
The airport in Haikou, capital of Hainan, has seen more than 50,000 inbound and outbound passengers every day since November. On Sunday, two days after Beijing's red alert was put in place, the airport welcomed 32,155 inbound passengers, the highest since the National Day holiday in October, according to data from the airport.