A day after the city breathed cleanest air, Mumbai on Sunday recorded an Air Quality Index (AQI) of 56, bringing the air quality down from ‘good’ to the ‘satisfactory’ category.
As per data from the System of Air Quality and Weather Forecasting and Research (SAFAR), the city's AQI on Friday was 10, which is the lowest-ever since the monitoring began in 2015.
According to SAFAR, the AQI of Mumbai will continue to remain in the 'satisfactory' category for the next two days.
However, on Sunday, the city crossed the 50 AQI mark for the first time since mid June. Back then, Mumbai had been witnessing good air-- mostly below AQI 20-after the onset of monsoon.
Explaining the reason for Sunday’s increase in AQI, SAFAR project director Gufran Beig, said, “There are many factors that affect the AQI of a particular region but the wind speed is one of the main factors; especially for a geographical region like Mumbai which is surrounded by sea on three sides.”
The increase and decrease in AQI for Mumbai largely depends on the speed of the wind which was high on Friday and low on Sunday, resulting in the increase and decrease of air quality throughout the city, he added.
There are six AQI categories namely ‘good’ (0 to 50), ‘satisfactory’ (50 to 99), ‘moderate’ (100 to 199), ‘poor’ (200 to 299), ‘very poor’ (300 to 399), and ‘severe’ (400 to 500).
Each of these categories is decided based on the ambient concentration values of air pollutants.
Meanwhile, the Indian Meteorological Department (IMD) has predicted moderate rain in the city and suburbs with a possibility of heavy rainfall at isolated places.
On Sunday, the minimum temperature recorded in Santacruz was 25.8 degrees Celsius and the maximum was 31.6 degrees Celsius, with 87 per cent relative humidity. Similarly, Colaba experienced a minimum temperature of 26.9 degrees Celsius and a maximum of 31 degrees Celsius, with 83 per cent relative humidity.