As Tuesday dawned residents of this heavily contaminated metropolis encountered exposed to dangerously toxic air that fell into the "severe" level.
Multiple areas of the city recorded an air quality index above 500, which translates to ten times the healthy level established by the WHO.
Certain monitoring stations, readings of PM2.5 and PM10 reached peaks of 1,800, representing 15-20x exceeding safe limits.
For the past four years, officials had maintained a total prohibition on the purchase and ignition of pyrotechnics during the Festival of Lights due to their substantial impact to the deadly haze that engulfs the city as winter sets in.
Nevertheless in recent months, the recently formed local government approached the highest court to seek a relaxation of the restrictions.
The suggestion was allowing "green crackers" – previously criticized by conservation groups as being only about 30% less polluting – as a middle ground between "cultural practices and ecological concerns".
Much to the frustration of public health and environmental advocates, the court agreed to the request, specifying that eco-friendly pyrotechnics could be set off during specific time windows throughout the celebrations.
During the celebrations, there was extensive flouting of the regulated periods across the capital, with little monitoring regarding whether the pyrotechnics being used were actually the eco-friendly variety.
Many recording stations throughout Delhi showed pollution spiking around the night hours to extremely hazardous readings seen during celebrations in at least recent memory.
The proliferation of firecrackers during the festival also sparked a blame game with bordering Pakistan, with representatives in Pakistan's Punjab pointing to declining air quality in their urban centers on hazardous particles coming from India following the events.
Extremely elevated levels of atmospheric toxins in the city have persisted as a significant problem for more than 15 years, with the problem gradually deteriorating.
Near Diwali, the levels of hazardous particles in the atmosphere has been observed to increase dramatically to 70% higher the most severe levels ever measured in the Chinese city, which was once viewed as the planet's dirtiest urban center.
The problem in the city is caused by a convergence of various sources including automobile exhaust, dust, construction activities, waste incineration and smoke from agricultural fires in neighbouring regions of Punjab and Haryana.
In these regions, agricultural workers illegally ignite agricultural waste to prepare for next season, generating hazardous smog that becomes contained over the city as winter air arrives.
Public health and economic consequences on the roughly thirty-three million people living in the metropolitan zone is significant, according to various research.
The contaminated air leads to high levels of nervous system, heart and circulatory and breathing diseases, and can potentially cause malignancies.
The pollution is calculated to be causing approximately 10k untimely mortalities each year in the capital.
Elara Vance is a digital strategist with over a decade of experience in tech consulting, specializing in helping UK businesses navigate digital transformation and IT innovation.