Mumbai logs AQI of 190, breathes cleanest air so far this year

Mumbai inhaled its cleanest air this year on Friday as westerly winds blowing from the north west of India cleared pollutants dispersed in the air. An overall air quality index (AQI)—a pollutant measuring indicator— of 190 was measured today, which was in the moderate category for the first time in 2021.

Air quality had remained in the poor to very poor category since the beginning of January owing to low temperatures. On January 8, the AQI was the worst at 317 (very poor) for this year. However, with the onset of westerly winds, the air has cleared up.

AQI was calculated by the System of Air Quality Weather Forecasting and Research (SAFAR) as the average of indices recorded at 10 locations in the city and suburbs. SAFAR categorises AQI levels for PM2.5 in the 0-50 range as good; 51-100 as satisfactory; 101-200 as moderate; 201-300 as poor; 301-400 as very poor and above 400 as severe.

“Winds blowing from the north and west have cleared the air of pollutants. If the wind continues, air quality will remain moderate for the next couple of days, despite a drop in temperatures. However, without the winds, air quality may become worse,” said a spokesperson from SAFAR. Navi Mumbai, however, recorded very poor air with the AQI being measured at 350. Along the western suburbs, Malad had the worst air with an AQI of 211 (poor).

Both day and night also turned pleasant on Friday as temperatures dropped significantly in the city providing relief from week-long heat conditions. At Santacruz, the minimum temperature dropped to 19.5 degrees Celsius, two degrees above normal. The Colaba observatory of the Indian Meteorological Department (IMD) recorded a minimum temperature of 21 degrees Celsius. While this was 2 degrees above normal, the minimum temperature was much lower than Monday’s minimum temperature of 23.5, the highest in a decade.

Maximum temperatures remained below normal in the city. Santacruz reported a maximum temperature of 31 degrees Celsius, which was 0.8 degrees below normal. At Colaba, the maximum temperature dropped a degree below 30 degrees Celsius and was 1.1 degrees below normal.

“IMD had forecast that temperatures would drop from Friday for the next few days as westerly winds have started blowing over parts of the state. Since, parts of north west India are under the influence of a cold wave, north-westerly winds from these parts are colder,” said KS Hosalikar, deputy director general of western region, IMD.