Rain impact lasts for 2nd straight day as air in Delhi bucks October trend

A day after the record-breaking downpour across the city, the air quality index (AQI) in Delhi remained below the 100-mark on Tuesday, according to data from the central pollution watchdog

A day after the record-breaking downpour across the city, the air quality index (AQI) in Delhi remained below the 100-mark on Tuesday, according to data from the central pollution watchdog.

At Lodhi Gardens in Delhi on Tuesday, as residents breathed relatively clean air a day after a record-breaking downpour. (Sanchit Khanna/HT Photo)

Delhi’s average AQI (at 4pm) on Tuesday rose marginally to 69, categorised as “satisfactory” by the Central Pollution Control Board (CPCB).

The AQI in Delhi was 46 on Monday — giving the city the cleanest October air in at least six years (for which the agency maintains pollution data). It was also the first “good” air day in Delhi in 413 days, a stretch going back to August 31 last year, when the AQI was 41.

An AQI between 0 and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

On Tuesday, the mercury in Delhi settled at a maximum of 28.8 degrees Celsius, officials said. The relative humidity was recorded at 65%, according to the India Meteorological Department (IMD). The minimum temperature in the national capital, meanwhile, settled at 22.4 degrees Celsius, officials said.

On Monday, the minimum temperature fell to 20.1°C.

The Capital’s air quality had steadily worsened all month, a decline that accelerated on Friday, when the AQI reached the far end of the “moderate” zone at 198.

On Saturday, as winds calmed, air pollution got worse and reached 284, before climbing to 298 the next day. It then fell by over 250 points on the back of the record October rain on Monday.

Between Sunday and Monday, the national capital recorded 87.9mm rainfall, the fourth highest in a day ever in October, and the highest since 1956, when the city received 111mm rain, according to IMD data.

The weather office did not give the day in October 1956 when the city received this record spell of rain.

IMD data shows that between 1910 and 2021, the period for which the agency has records, single-day October rain peaked at 172.7mm in 1954, which was also the wettest October, recording 238.2mm rain.