The India Meteorological Department (IMD) data on Monday showed that Mumbai’s maximum temperature touched 35.9 degrees Celsius, registering a departure of three degrees above normal.
The city has witnessed a significant increase within a day, with the maximum temperatures for Santacruz observatory recorded at 33 degrees Celsius between Sunday and Monday morning and then soaring to 35.9 degrees on Monday afternoon.
Data procured from the weather station shows that while this is not the highest recorded October temperature, high temperatures are usually recorded in the fag end of the month, making Monday’s temperature rise an anomaly.
Between 2011 and 2020, the highest maximum October temperature was recorded at 38.6 degrees in 2015 on October 17, whereas the second highest recorded temperature (38 degrees) was registered in 2018 on October 28.
In an interview, Sushma Nair, scientist from IMD Mumbai said the city will experience an escalation in warmth with the temperatures hovering around yesterday’s temperature of 36 degrees, for the next 2-3 days at least.
“On Monday, Mumbai’s Santacruz weather station recorded 35.6 degrees. There are dry easterly and north easterly winds in the lower levels owing to which there has been a sudden rise in the temperatures. The city will experience such high temperatures for the next 2 – 3 days at least.”
Raghu Murtugudde, Professor of climate studies at IIT Bombay, told that the movement of the easterly winds implies that the monsoon winds have completely retreated and winds from the north-northeast are picking up.
“As they come down the Western ghats, they can become warmer and create warm temperatures. Furthermore, it is warming over the Middle East and the Mediterranean and desert winds are blowing towards Mumbai. This can be another potential reason for the heatwaves,” said Murtugudde on Monday.
Despite the city’s sweltering conditions, experts emphasize that the ‘October heat’ has not arrived yet. A common weather phenomenon for Mumbai, ‘October Heat’ leads to escalation in temperatures from the first week of October each year with the daily temperature rising and ranging between mid-30 – 35 degrees Celsius.
Responding to questions, Murtugudde maintained that the city has not experienced October heat so far. Explaining the October heat phenomenon, he added, “Once the summer monsoon ends and monsoon retreats, the cooling effect of the northeast winds does not commence immediately.
October is the month of transition or the inter-monsoon month. The oceans around are still warm and the weak winds set up high pressure over much of India and create conditions for heatwaves.” Meanwhile, referring to October heat as the ‘second summer’, Mahesh Palawat from Skymet Weather Services said, “When south-west monsoon withdraws, humid winds are reduced. Furthermore, the positioning of rays is not slant. Owing to these factors, Mumbai and its neighbouring areas experience increased temperatures during the transition phase between monsoon and winter season, until the northerly winds set in and reduce the temperatures.”
