Delhi Achieves Cleanest Air Quality of the Year After Record September Rainfall

New Delhi: Delhi on Friday experienced its cleanest air quality of the year after witnessing record rainfall in September. The national capital recorded an Air Quality Index (AQI) of 52, nearing the edge of "good" and "satisfactory" AQI classifications. Delhi has exceeded both its annual and seasonal average rainfall in the early days of September, with total rainfall crossing the 1,000 mm mark well above the normal level while residents enjoyed the cleanest air of the year so far.

The heavy rains, caused by a depression and active monsoon trough, helped clear pollutants from the air. 

The accompanying winds, blowing at speeds of 30-40 kmph, further dispersed the remaining contaminants. Nearby areas also saw improved air quality. 

Faridabad's air quality improved significantly, recording a 24-hour average AQI of 24. Nearby cities also showed good air quality, with Ghaziabad at 34 and Noida at 46. 

Gurugram reported an AQI of 69, while Bulandshahr had 21, Meerut 28, and Muzaffarnagar 29.

This improvement is linked to recent weather patterns, including depression activity and an active monsoon trough that brought substantial rainfall to the Delhi NCR region. 

The rain washed away pollutants, and winds of 30-40 km/h helped disperse remaining contaminants.

Delhi itself exceeded its annual and seasonal average rainfall in early September, with total rainfall surpassing 1,000 mm.On Friday, Palam recorded 54 mm of rain, and Safdarjung received 30.9 mm between 2:30 and 5:30 pm. 

September 2024 has already seen 125.8 mm of rainfall, which is 55% above the normal amount, and surpasses the monthly average. In contrast, September 2023 had only 82.7 mm of rainfall, which was 33% below the average.

Rainfall is categorized as "heavy" when between 64.5 mm and 115.5 mm, "very heavy" from 115.6 mm to 204.4 mm, and "extremely heavy" when above 204.5 mm. The AQI scale ranges from "good" (0-50) to "severe" (401-500), with "satisfactory" (51-100) indicating minimal risk.