Air quality in Mumbai was ‘very poor’ between Sunday night and Monday morning, as the air quality index (AQI) – a pollution-measuring indicator – touched 306, the same as Delhi.
But pollution levels in the city fell to 265, categorised as ‘poor’, in the evening, while Delhi’s worsened to 319.
The System of Air Quality and Weather Forecasting and Research (SAFAR), which monitors and forecasts air quality, has predicted that pollution levels in Mumbai will further decline and will remain around 260.
“Our readings are based on average readings over the past 24 hours. We observed that air quality worsens during night time because pollutants are closer to the earth’s surface because of a drop in temperatures. The pollutants move up during the day, get dispersed as temperatures rise, which improves the city’s air quality,” said Neha S Parkhi, senior programme officer, SAFAR, adding that this had been the general trend during the winter months.
Meanwhile, there was a rise in night temperatures in the suburbs on Monday. From Sunday’s 16.4 degrees Celsius, or 0.8 degree Celsius below normal, the minimum temperature increased to 17 degrees Celsius, 0.1 degree Celsius above normal on Monday. The night temperature shot up by a degree Celsius at South Mumbai on Monday— 20.8 degrees Celsius.
On the other hand, day temperatures fell by almost a degree Celsius as Colaba recorded 31.3 degrees Celsius, 1.8 degree Celsius above normal. The maximum temperature at Santacruz continued to be three degrees Celsius above normal at 33.7 degrees Celsius on Monday. “The city continues to experience easterly winds (hot winds from the land) that have kept temperatures above normal. We expect night temperatures to remain at the current level for the coming days,” said VK Rajeev, director, western region, India Meteorological Department.
Moisture levels were much lower in the city, as 64% and 77% humidity was recorded at Santacruz and Colaba, respectively. Weathermen have predicted clear skies for Tuesday with day and night temperatures at 34 degrees Celsius and 17 degrees Celsius respectively.