Days of heavy smog are likely to strike Beijing again as no gusty winds are foreseeable this week, meteorological reports have showed.

The city's air quality dropped significantly Monday morning and the pollution level reached grade five in some places -- indicating severe pollution?-- on a six-grade pollution gauging system, according to Beijing Municipal Environmental Monitoring Center.

The mountain area in north Beijing maintained good air conditions until Sunday, while the six districts in downtown Beijing and the southern area already have suffered slight or even moderate pollution.

Readings of PM2.5, which measure airborne particles smaller than 2.5 micrometers, hit around 160 on Monday morning, the center said.

Heavy wind is becoming the most effective way to dispel smog in North China, where little rainfall is expected in spring.

No heavy wind is likely to hit the city until March 31, said Beijing Meteorological Bureau.

A seven-day-long spell of haze choked northern and eastern China in late February. Regions affected included Hebei, Shanxi, Shandong, Henan and Liaoning provinces as well as Beijing and Tianjin Municipalities.

Beijing reported 58 days of serious pollution in 2013, according to the Beijing Municipal Environmental Protection Bureau. The average PM2.5 reading was more than double the new national standard of 35 micrograms per cubic meter.