Mumbai weather updates: City sweats and shivers as weather plays yo-yo

A dense shroud of fog obscures Nariman Point in south Mumbai. Pic/Shadab Khan

City meteorologists and weather enthusiasts are intrigued by the sharp temperature fluctuations in Mumbai over the past three days. The sudden dip to 13.7 degrees C on Monday (December 9) made it the coldest December day in nine years. However, within 48 hours, by Wednesday, the temperature rose sharply to 20 degrees C, leaving many puzzled by this "unexpected" and "unusual" phenomenon.

Officials from the India Meteorological Department's (IMD) Regional Meteorological Centre (RMC) in Mumbai, however, stated that this variation in temperature was anticipated. After enduring several days of unusually high temperatures, the IMD's Santacruz weather observatory reported a minimum temperature of 13.7 degrees C on Monday, which is 5.6 degrees C below the average.

Similarly, the Colaba observatory recorded a minimum of 19.2 degrees C. This represents a notable decline of over 11 degrees C over the last three days, as the minimum temperature in Mumbai had remained around 25 degrees C until Friday morning. On Wednesday, the Santacruz weather observatory recorded a minimum temperature of 20 degrees C, whereas the Colaba observatory recorded a minimum of 22.6 degrees C.

Sushma Nair, a scientist with IMD's RMC Mumbai, told mid-day, "We had expected a dip and rise in temperature thanks to the active northerly winds. The temperature was expected to dip to 15 degrees C, but it dropped to 13 degrees C. Simultaneously, there is also a well-marked low-pressure area in the Bay of Bengal. In such conditions, these kinds of fluctuations happen."

Calling this a mysterious case of an isolated 13.7 degrees C on December 9, climatologist Rajesh Kapadia from private weather blog 'Vagaries of the Weather', said, "It is very difficult to explain this ‘out of turn' phenomena… this seems very unbelievable. Temperature rising by 5 degrees C in 24 hours and 6.3 degrees C in 48 hours is unnatural. We cannot imagine a sudden dip and sudden rise in temperature for a day, and that too in a very isolated pocket."

"A sharp dip and rise in temperature within a week, particularly over the last three days, is fascinating and warrants further study. The fluctuation in temperature last week was due to northerlies and the aftereffects of Cyclone Fengal. The December 9 temperature of 13.7 degrees C seems somewhat unusual to me, but since the IMD has reported it, I trust it is accurate. However, I would urge the IMD to publish the weather phenomenon behind this abrupt fluctuation on their website for greater transparency and understanding," said a meteorologist from a private weather forecasting agency.

Meanwhile, independent weather enthusiast Rushikesh Agre, popularly known for his social media handle ‘Mumbai Rains' on X, wrote on Wednesday: "Bit of a rise in temperatures than expected in the last 36 hours. Santacruz was 20 degrees C today. Yet, temperatures are unlikely to stay above 20 degrees C for the next two weeks. Areas closer to SGNP will be below 18-19 degrees C… Thane and Navi Mumbai below 20 degrees C for the rest of the week. Maximum temperatures, on the other hand, will unfortunately be warm for the next three to four days. Short update on this soon."