The storm caused an unprecedented spike in air pollution measurements - with pollution levels in some districts at 160 times the recommended limit.
Hundreds of flights were cancelled or grounded as the sky was covered by an apocalyptic-looking orange haze.
The sand is being brought in by strong winds from Inner Mongolia.
In Mongolia the severe sandstorms have reportedly caused six deaths and left dozens missing.
China's Global Times media outlet reported that at least 12 provinces in the country, including the capital, had been affected, and the weather was likely to continue through the day on Monday before improving at night.