Maximum temperature drops in Delhi but high humidity brings no respite

IMD said the monsoon is likely to cover several parts of northwest India over the next three to four days

The mercury dropped below 40 degrees Celsius (°C) in Delhi on Tuesday but there was no respite from the heat as high humidity levels made outdoors unbearable. Delhi recorded a maximum temperature of 39.7°C, three degrees above normal and down from 40.4°C on Monday, and the heat index (HI) or “real feel” temperature was recorded at 52°C, a drop from 53°C the day before.

A security guard at Kartavya Path in New Delhi on Tuesday. (Sanjeev Verma/HT Photo)

The India Meteorological Department (IMD) has issued a yellow alert for Delhi, forecasting rain across parts of the city for the next six days. IMD said the monsoon is likely to cover several parts of northwest India over the next three to four days, but did not specify when the south-west monsoon would likely hit the Capital.

“Delhi will see light rain till the end of the month. The intensity of rain is expected to increase from June 28, when we will see the impact of a western disturbance and the monsoon advancing further into parts of northwest India,” said an IMD official.

Delhi’s maximum had dropped below 40°C for the first time in 40 days on Saturday to 39.4°C. It was 39.8°C on Sunday before it rose to 40.4°C on Monday.

In its monsoon bulletin on Tuesday, IMD said conditions were currently favourable for the south-west monsoon to advance into “the remaining parts of the North Arabian Sea, Gujarat and Madhya Pradesh, some more parts of Rajasthan, the remaining parts of Chhattisgarh, West Bengal, Jharkhand and Bihar, most of eastern Uttar Pradesh, parts of west Uttar Pradesh, parts of Uttarakhand, Himachal Pradesh, Jammu-Kashmir-Ladakh-Gilgit-Baltistan-Muzaffarabad, and the northern parts of Punjab and Haryana in the next three to four days.”

Delhi’s relative humidity on Tuesday oscillated between 48% and 92%, making sweating difficult outdoors — higher humidity makes it difficult for the human body to sweat and cool itself effectively. The wet bulb temperature — a measure of how difficult or easy it is for the human body to be outdoors, was 29.6°C on Tuesday, marginally lower than the 29.7°C on Monday.

A wet bulb temperature of 32°C or higher makes it difficult for even fit and acclimatised people to work outdoors for long and at a wet bulb temperature of 35°C — the maximum threshold — humans can no longer regulate body temperatures, leading to heatstroke and potential collapse.

Meanwhile, Delhi’s minimum temperature was 28.6°C on Tuesday, a degree above normal and a drop from 31.4°C a day earlier. According to IMD forecasts, Delhi’s maximum will likely stay below 40°C till the end of the month, dropping to 36°C by June 29 due to an increase in rain intensity. The minimum may dip to 25°C by June 29 and 23°C by June 30, making for a relatively cooler end to the month.