IMD forecasts heavy rain in Delhi for June 29-30; no word yet on arrival of monsoon

New Delhi: Pre-monsoon showers on Wednesday kept Delhi’s maximum temperature below 40°C for the second successive day, but kept humidity levels high, said the India Meteorological Department (IMD).

The weather agency also announced the arrival of monsoon over large parts of northwest India over the next three to four days, but the list did not specify a date for Delhi, indicating that monsoon will not arrive on its usual date of June 27.

In a seven-day forecast for the Capital, the Met department has forecast rain till the end of the month, with the showers expected to intensify on the last two days of the month, which could signify the arrival of monsoon, said weather experts.

The weather agency has forecast light to moderate rain in Delhi on June 29, issuing a yellow alert for the day, and moderate to heavy rain on June 30, issuing an orange alert.

“We are expecting an increase in rain intensity in northwest India from June 28 and monsoon could reach Delhi on June 29 or 30. Delhi-NCR may see heavy rainfall spell during this period, based on which the onset of the monsoon could be declared,” said Mahesh Palawat, vice president at Skymet, a private weather forecasting service.

An IMD official, however, said they will declare the likelihood of monsoon onset over Delhi as and when it draws nearer.

Although no rainfall was recorded at the Safdarjung station, which is representative of Delhi’s weather, Palam station recorded 2.3mm of rainfall between 8.30am and 5.30pm and Ayanagar station recorded 1.8mm of rainfall in the nine-hour period.

The Lodhi Road and Ridge stations both recorded “trace” rainfall.

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

Delhi recorded a maximum temperature of 39°C on Wednesday, which was two degrees above normal, but the heat index (HI) or “real feel” temperature was 52°C, the same as the past two days. Delhi’s maximum temperature was 39.7°C on Tuesday and 40.4°C on Monday.

The minimum temperature on Wednesday, meanwhile, was 31.6°C, which was four degrees above normal and marking a difference of only 8°C between the two extremes.

“We saw cloudiness both during the day and at nighttime. During the day, it keeps the maximum low, but at night, the same cloudiness does not allow a lot of heat to be lost either,” the IMD official cited above said.

Delhi’s humidity remained high, between 51% and 71%, on Wednesday, keeping the wet-bulb temperature — a measure of how difficult or easy it is for the human body to be outdoors — at 29.3°C, which was marginally lower than the 29.6°C recorded on Tuesday.

The higher the humidity, the more difficult it is for the human body to sweat and thus, cool itself effectively.

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 temperature, leading to heatstrokes and potential collapse.

The IMD forecast a maximum temperature of 38°C and a minimum of 29°C for Thursd