What caused the spike in Delhi's air pollution?

According to the article, the spike in Delhi's air quality index (AQI) from 279 to 373 over a 24-hour period could be attributed to both a genuine increase in pollution and potential underreporting of the index on the previous day.

How did satellite data compare to the official air quality readings in Delhi?

The satellite-derived forecasts of PM2.5 concentrations showed a much smaller spike compared to the official air quality data, suggesting the official readings may have underestimated the actual pollution levels.

Home / Environment / Delhi's Air Quality Plummets, Raising Concerns Over Underreporting

Delhi's Air Quality Plummets, Raising Concerns Over Underreporting

Q: What were the reactions of Delhi residents to the air quality during this period?

The article states that residents reported a visibly dense haze in the city for the past three to four days, contradicting the relatively lower AQI readings on those days, further fueling doubts about the reliability of the air quality monitoring system.

31 Oct

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Summary

Air quality index in Delhi spiked from 279 to 373 in 24 hours
Satellite data shows pollution spike larger than official readings
Residents report visible haze, contradicting lower pollution numbers

Delhi's Air Quality Plummets, Raising Concerns Over Underreporting

On October 30, 2025, Delhi's air quality index (AQI) spiked by almost 100 points, from 279 to 373, over a 24-hour period. This sharp increase in pollution levels has raised concerns about the accuracy of air quality monitoring in the city.

According to the analysis, the spike in AQI could be attributed to both a genuine increase in pollution and potential underreporting of the index on October 29. Satellite imagery and modeled estimates of pollution suggest that the spike recorded on October 30 was much larger than the forecasts, particularly in the early hours of the day.

Residents of Delhi have also reported a visibly dense haze in the city for the past three to four days, contradicting the relatively lower AQI readings of 294 and 279 on October 28 and 29, respectively. This discrepancy between the official data and the perceived air quality has further fueled doubts about the reliability of the air quality monitoring system.