Mumbai’s air quality falls as rains recede; temperatures go up

Large parts of Mumbai woke up to hazy skies and poor quality of air on Saturday, with the monsoon season coming to an end.

Mumbai’s average air quality during the day, according to System of Air Quality Weather Forecasting and Research’s (SAFAR) pollution-measuring air quality index (AQI), stood at 128 — classified as ‘moderate’. The index measures the amount of small pollutant particles in the air that can easily enter the lungs. By evening, the AQI measured 140 . Of 10 locations in the city where the air quality was monitored, Worli was the most polluted with an AQI of 298 (classified as poor), followed by Andheri with AQI of 295 (poor).

When AQI levels are between 0 to 50, the air quality is considered good, from 51 to 100 is satisfactory, 101 to 200 is moderate, 201 to 300 is poor, 301 to 400 is very poor, and above 400 is considered severely polluted air.

The India Meteorological Department (IMD) attributed the haze and drop in the quality of air to the transition of seasons. “The monsoon is in withdrawal mode. The dry air flowing in from the northern parts of the country is mixing with moisture coming in from the Arabian Sea and Bay of Bengal, giving rise to the haze,” said Ajay Kumar, the director, western region, IMD.

Officials said the haze, thundershowers and lightning will continue till the monsoon fully withdraws. Further, the incursion of dry air will result in a rise in day temperatures.

There was no rain recorded on Friday, and maximum temperature rose a degree above normal, to 32.6­°Celsius in the suburbs. It was 32 ° Celsius in south Mumbai.

Minimum temperatures dropped in south Mumbai by 3°Celsius to 21.8°degrees Celisus, while it was normal, at 25.4°C in the suburbs. Humidity levels at Colaba and Santacruz was at 80% and 71%.

The IMD has said thundershowers are very likely to take place towards the evening or night in the city and suburbs on Saturday, with maximum temperatures of 34°C, and minimum temperatures of 24°C.