Haryana and western Uttar Pradesh burn crop remains to clear their fields for the next sowing cycle.

Northwest winds coming from these states will also pick up speed gradually, carrying smoke from stubble burning into Delhi, according to air quality forecast agency SAFAR.

India’s pollution problem, however, is not just limited to Delhi and Indian cities routinely dominate global pollution rankings.

Last week, India’s financial capital Mumbai witnessed a drop in air quality, overtaking Delhi several times this month. Officials said that withdrawing rains and constructions work caused the rise in pollution levels in the city.