28th February...Post

We see the air quality for Mumbai and throughout Western Maharashtra, improving to "Satisfactory Levels".

And,we hear and read many possible reasons from "1000 constructions stopped in Mumbai " to " more running of EVs"..could not be more impractical than realistical.

And these conclusions improve the AQI all over Western Maharashtra!

Well, this is not new...the real reason is meteorological changes.

Basically the main meteorological factors that are required for cleaner air are:

1) Strong winds in lower 2 km of the atmosphere 

2)No temperature inversion 

3)Rain

While rain can be the most effective, Strong winds help disperse the particulate matter and ensure clear skies and high visibility even if there is some temperature inversion at night.

The main thing that changed across western Maharashtra from 25th Feb to 26th Feb was increased wind speed which ensured that no dust or particulate matter gets trapped and stagnated in the lower 1-2 km of the atmosphere. 

This is the main reason for improved AQI and good visibility.

Currently, Mumbai ranks among the cleanest cities in the country at 6 PM as per live AQI data from IQAir. Along with Mumbai, Pune, Thane, and NaviMumbai are also featuring in the top 10 cleanest cities list — notably without any rainfall activity.

This clearly shows how meteorological conditions play a dominant role in air quality. Despite being regions with intense urbanisation and ongoing construction activity, air quality has improved significantly due to stronger winds and better atmospheric mixing caused by an active weather system, which dispersed accumulated pollutants.

At the same time, several non-metro towns with comparatively lower construction activity are appearing in the top polluted list. This highlights an important scientific reality:

Pollution levels are not determined only by construction or urban density, but largely by local weather conditions, ventilation, and atmospheric stability.

When ventilation improves, even dense metros can record clean air; when calm and stable conditions persist, pollution can build up even in smaller cities. Weather decides dispersion — emissions alone don’t explain day-to-day AQI swings

Now, next week, all the " Constructions" will restart and Mumbai AQI will increase to around 170 levels.

NE winds will commence and heat will increase...Full report on Sunday 1st March ( night).