Until mid-December, Delhi’s monthly average air quality remained the cleanest in the past five years. However, the respite was short-lived as the air quality worsened to the ‘very poor’ category with an average Air Quality Index (AQI) of 379 Monday.

The GRAP-4 curbs entail a ban on trucks except for those carrying essential items or using clean fuel. Construction activities at public projects have been temporarily halted while non-essential light commercial vehicles registered outside Delhi were prohibited, except for EVs and CNG and BS-VI diesel ones.

Delhi's air quality level is likely to worsen in coming days amid possible cold wave conditions and dense fog across North India.