In a respite from the deteriorating air quality, Mumbai and its neighbouring districts like Thane are set to experience intermittent spells of moderate rain and thunderstorms with the India Meteorological Department (IMD) sounding a yellow alert in the region between Friday and Saturday. According to the weather bureau, rain is here to stay at least until Tuesday.
Even as the southwest monsoon’s withdrawal was announced on October 10, the city has been experiencing thunderstorms with heavy showers since Tuesday evening. A day after Diwali festivities on October 20, heavy showers lashed the region starting from Navi Mumbai and pockets like Badlapur in Thane, to large pockets of Mumbai. Data from Brihanmumbai Municipal Corporation’s (BMC) automatic weather stations showed that between 6 pm and 7 pm Tuesday, heaviest rain was recorded in Dharavi at 19 mm, followed by 16 mm in Pratiksha Nagar, 15 mm in Chembur, 11 mm in Powai, and 10 mm in Dadar and Goregaon.
The showers continued into Wednesday, when, after experiencing above-normal temperatures of 35.5 degrees Celsius during the day, moderate rain swept through parts of the city and its neighbouring districts.
According to IMD, rain activity is slated to intensify between Friday and Saturday, placing Mumbai, Thane and Palghar districts under a yellow alert owing to the possibility of gusty winds at the speed of 30-40 kmph, moderate rainfall as well as thunderstorms accompanied with lightning.
Despite rain during the evenings, temperatures remained above normal, with day time temperatures on Thursday touching 36 degrees in the suburban Santacruz observatory while in Colaba the maximum temperatures touched 35 degrees.
While no alerts have been sounded after Sunday, meteorologists have said that light to moderate showers will continue until Sunday. In neighbouring districts of Raigad and Ratnagiri, a yellow alert has been sounded for three days until Saturday.
Speaking to The Indian Express, scientists from IMD Mumbai attributed the unseasonal spells of rain to easterly winds troughing across Maharashtra in the lower levels.
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“The troughing from the easterly winds has led to the incursion of moisture. Furthermore, the high temperatures during the daytime have favoured the development of thunderstorms and rainfall during the evenings,” said an IMD scientist.
So far, the Colaba observatory has already clocked in 88.5 mm rain in the month of October, making for a surplus of 19 mm for the season.
The spell of rain that swept the city a day after Diwali festivities Monday spurred Air Quality Index (AQI) levels into the “poor” category at 212, making it the city’s worst air quality since the onset of monsoon in May.
A spell of rain swept the city a day after Diwali festivities on Monday, which had spurred the Air Quality Index (AQI) levels into the “poor” category at 212, making it the city’s worst air quality since the onset of monsoon in May.
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After showers lashed the city, the air quality improved significantly on Wednesday morning to 134 and further dipped to 116 on Thursday morning. With rain droplets settling down pollutants suspended in the atmosphere, the city is likely to experience improved air quality until the end of the week at least.
Oct most polluted month of Mumbai: CPCB data
For Mumbai, October has emerged as the most polluted month of the year so far with the worst deterioration recorded between October 18 and October 22, according to an analysis by the Centre for Research on Energy and Clean Air (CREA). Data from the Central Pollution Control Board (CPCB), compiled by CREA, showed that 19 monitoring stations of the city recorded their highest daily average PM2.5 levels in October while 7 monitoring stations logged peak PM10 levels since January over the past few days. The analysis showed that PM2.5 and PM10 were amongst the key pollutants impacting Mumbai’s air and people’s health, during the month.
“October 2025 stands out as Mumbai’s most polluted month so far this year, with air quality levels peaking across several parts of the city,” said Manoj Kumar, Analyst with CREA.
