Loo, humidity give Delhi a real feel of 43°C: IMD

In the early hours of Sunday too, the Capital saw a brief spell of rain with Palam recording 1.2mm of rainfall

Delhi on Sunday reeled under a combination of humidity and hot surface winds, or Loo, despite a fall in temperatures. While strong surface winds of up to 30kmph are expected to continue over the next three days, light rain on June 15 and 16 will bring some respite, the weather department has predicted.

A mirage on a hot and humid day, at Kartavya Path in New Delhi on Sunday. (Vipin Kumar/HT Photoimes)

In the early hours of Sunday too, the Capital saw a brief spell of rain with Palam recording 1.2mm of rainfall in a 24-hour period till 8:30 am on Sunday, while Safdarjung – representational of Delhi’s weather — received 0.5mm.

While this led to the slight drop in mercury to 38.5 degrees Celsius (°C)– one degree below normal, and nearly three degrees in comparison to Saturday’s 41.8°C — an increase in levels of relative humidity to 38% meant that the heat index (HI), or, more colloquially, “real feel temperature”, hovered around 43°C on Sunday, according to the Indian Meteorological Department (IMD).

“Temperatures may have dipped at most stations by 2 to 3 degrees, but we saw strong surface winds of over 30kmph post noon and the humidity levels increased by around 30% at Palam on Sunday as compared to Saturday. Both these reasons made it feel warmer than what it actually was,” said Kuldeep Srivastava, scientist at IMD .

HI is a calculation that represents conditions in the shade and prolonged exposure to a heat index of 26–32°C will likely cause fatigue in many people, while 32–40°C is widely associated with sunstroke, and 40–54°C with heatstroke.

While the actual maximum temperature varied from 37.5°C at Mayur Vihar to 42.4°C at the Delhi University weather station, IMD data showed that humidity levels oscillated between 38% and 70%, respectively, in the last 24 hours.

While IMD does not calculate HI yet for individual stations, it has begun giving out HI-based forecasts this summer onwards, identifying which parts of the country are most likely to be impacted by a combination of high humidity and temperature.

In terms of minimum temperature, Delhi recorded a low of 25.2 degrees — three degrees below normal. It was 26.7°C a day earlier.

Forecasts show that loo is expected on Monday and Tuesday too, with the maximum to return to 40°C at Safdarjung, while touching 42 to 44 degrees at other locations. The minimum will, meanwhile, hover between 26 and 27 degrees, IMD predicted.

Later on June 15 and 16, Delhi, the national capital region, and other parts of northwest India may see light rain with Cyclone Biparjoy expected to cross Saurashtra and Kutch and adjoining Pakistan coasts on June 15. “Moisture from the Arabian Sea will reach NCR in the form of southwesterly winds, leading to chances of light rain on both days,” a weather official said.

In terms of air quality, Delhi’s air remained in the moderate category, with the 24-hour average air quality index (AQI) recorded at 130, according to the Central Pollution Control Board’s national bulletin at 4pm. It was a day earlier. AQI is forecast to remain in the moderate range till Wednesday.

CPCB classifies an AQI between 0-50 as good, between 51 and 100 as satisfactory, between 101 and 200 as moderate, between 201 and 300 as poor, between 301 and 400 as very poor and over 400 as severe.