Mumbai’s skyline often appears clearer and fresher during monsoon showers but in the days that follow, many residents are left puzzled when the Air Quality Index (AQI) shoots up again. What seems like cleaner air turns heavy and hazy once the rain subsides, pushing the city’s AQI into the “poor” or even “very poor category".
Why Does AQI Rise After Rain?
Rain temporarily cleanses the air by washing away dust, pollen, and pollutants. However, this cleansing effect is short-lived. Once the rain stops and humidity rises, pollutant particles get trapped close to the surface due to reduced wind speed and temperature inversion, a phenomenon where cooler air near the ground prevents pollutants from dispersing upwards.
Additionally, construction dust, vehicular emissions, and industrial smoke quickly return to the atmosphere after rainfall. The high moisture in the air further binds fine particulate matter (PM2.5 and PM10), making it heavier and harder to disperse. The result, a sharp spike in pollution levels within 24 to 48 hours after the last spell of rain.
As per real-time data from IQAir.com, Mumbai’s Air Quality Index (AQI) touched 164 on Tuesday morning, placing it in the “unhealthy” category. The reading reflects a steady deterioration in the city’s air quality over the past week.
Common Triggers Behind Mumbai’s Bad Post-Rain AQI
Increased humidity: Keeps pollutants suspended in the lower atmosphere.
Reduced wind flow: Limits air circulation and dispersal of pollutants.
Ongoing construction: Dust and debris accumulate rapidly after rainfall.
Vehicular emissions: High traffic post-rain adds to the pollution load.
Festive activities: Crackers, garbage burning, and idol immersion contribute to rising particulate matter.
Do’s and Don’ts During Poor Air Quality Days
Do’s:
Wear an N95 mask if you need to be outdoors for long periods.
Keep windows closed during peak pollution hours, especially early morning and late evening.
Use air purifiers at home or offices if possible.
Stay hydrated - drinking plenty of water helps flush toxins from your system.
Include foods rich in Vitamin C and antioxidants to strengthen lung health.
Don’ts:
Avoid morning walks or outdoor workouts when AQI is poor.
Don’t burn garbage or leaves, as it adds to particulate pollution.
Avoid using firecrackers or incense during periods of stagnant air.
Refrain from long drives unless necessary — idling vehicles worsen air quality.
Looking Ahead
While rain provides temporary relief from dust and heat, Mumbai’s air quality woes quickly return due to rising emissions and stagnant air conditions. Environmental experts suggest stricter control on construction dust, vehicular pollution, and waste burning to help the city breathe easier once the skies clear.
