After a scorching start to the week, with temperatures touching 40 degrees in Mumbai, the city is expected to get slight relief from Wednesday as the mercury is likely to dip, according to the India Meteorological Department (IMD). Weather officials said the decline in temperature will be gradual, offering some respite after the unusually intense early-March heat.
mid-day contacted Sushma Nair, scientist at IMD Mumbai, to seek clarity on some burning questions.
Why has Mumbai’s temperature touched 40 degree C so early in the season?
There is an anticyclonic circulation over Gujarat and its neighbourhood, bringing dry easterlies over the region. This stalls the sea breeze, which generally moderates the temperatures of coastal cities. Therefore, the maximum temperature rises. Yesterday [Monday], the temperature in Santacruz was 6 degree C above normal. There is no western disturbance or any other system affecting the temperature, and it is only the effect of the anticyclonic circulation.
What is the forecast for Mumbai over the next few days?
The effect of the anticyclone will diminish from today [Wednesday], and the maximum temperature is expected to fall over North Konkan. On Tuesday, we issued orange alerts for Palghar, Mumbai, and Thane. For Wednesday, a yellow alert has been issued for North Konkan, warning of hot and humid conditions.
Does this qualify as a heatwave according to the IMD criteria for coastal cities?
Yes. The maximum temperature should be 37 degree C or more, and its departures from normal should be more than 4.5 degree C. Around 4.5 degree C to 6.4 degree C departures from normal qualify for a heatwave. Any departures from 6.5 degree C and above qualify to be termed a severe heatwave.
Are such high March temperatures becoming more frequent in Mumbai?
Last year, too, a severe heatwave was recorded in the first week of March. This is transition season, so March generally records high temperatures. Stay hydrated and avoid long exposure to the sun.
Heat can prove deadly
‘With temperatures rising above 38 degree C and high humidity in Mumbai, we commonly see cases of dehydration, heat exhaustion, heat cramps, heatstroke, low blood pressure, and worsening of pre-existing heart or kidney conditions. The combination of heat and humidity makes it harder for the body to cool itself through sweating, increasing the risk of heat-related illnesses’
– Dr Rahul Gupta, intervention cardiologist, Gleneagles Hospital, Mumbai
