The southwest monsoon withdrew from Mumbai on October 3, and the city immediately felt the heat. Colaba recorded 37.4 degrees Celsius on October 2, the highest October temperature there in at least 13 years, the IMD said.

The reading was 5.6 degrees above normal. The Santacruz observatory recorded 36.9 degrees, 4.6 degrees above normal. The IMD linked the sharp rise to the changing conditions of the monsoon withdrawal.

The withdrawal came five days early. It is Mumbai’s second-earliest monsoon exit in 25 years, according to reports. Of Maharashtra’s 36 districts, 20 recorded deficient rainfall this season.

High humidity made conditions uncomfortable across the city. South Mumbai stayed warmer than the suburbs, and even the early morning hours ran hotter than usual, with Colaba logging 27.5 degrees at 5:30 a.m.

The shift matters for commuters, outdoor workers and older residents. Officials advise staying hydrated and limiting exposure during peak afternoon heat, even though the calendar has moved past summer.