Heatwave conditions continue in parts of Delhi

The high temperature meant that parts of the city recorded heatwave or heatwave-like conditions for a fourth day this June.

Clear skies and dry westerly winds meant there was no relief from the relentless heat for Delhi, with the Capital recording a maximum temperature of 44.8 degrees Celsius (°C) – five degrees above the normal for this time of the year, and marginally above the 44.7°C the previous day.

People on hot day at Red Fort in New Delhi. (Raj K Raj/HT Photo)

The high temperature meant that parts of the city recorded heatwave or heatwave-like conditions for a fourth day this June.

The India Meteorological Department (IMD) defines a “heatwave” in a region where the maximum temperature is over 40°C, and 4.5°C above normal, or when the actual maximum temperature reaches 45°C or more for two consecutive days. This becomes a “severe heatwave” when the maximum is 6.5°C above the normal.

The department forecast no relief in the coming days either, with a heatwave alert in place for the National Capital Region till June 19, and Delhi’s maximum likely to hover around the 44-45 degrees mark during this period.

“We are seeing strong yet dry westerly and northwesterly winds at present. There is no significant cloud cover either and direct sunlight is impacting most parts of northwest India. This has led to a gradual rise in temperature over the last few days, and it could rise further in the next couple of days,” said an IMD official, adding that an orange alert is in place till Saturday.

The Safdarjung observatory — representative of Delhi — recorded a high of 44.8°C on Thursday — the fourth day in June that the station recorded heatwave conditions. This was the highest for the month since 2014, when Delhi recorded seven heatwave days for June.

Other parts of the city were even warmer, with Pusa in west Delhi logging the highest maximum for the day at 47.2°C, followed by Jafarpur in southwest Delhi at 46.6°C.

Thursday’s dry heat meant Delhi’s Heat Index (HI) or “real-feel” was actually slightly lower than the actual temperature at 44.1°C. Delhi’s wet-bulb temperature, another indicator of discomfort levels, was between 23.2°C and 25.1°C on Thursday. A wet-bulb temperature of 32°C or higher makes it difficult for even fit and young 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 heat strokes and potential collapse.

The minimum, meanwhile, was 29.4°C, which was a degree above normal. It was 28.5°C the previous day.

So far this month, there have been three spells in which at least one weather station in the city has recorded heatwave conditions. The first spell was May 17-20, before moist easterly winds led to a drop in temperature. A second spell lasted 12 days (May 25 to June 5), with the maximum at Safdarjung touching as high as 46.8°C on May 29. The third heatwave spell began on June 9, and forecasts show that it could continue till June 19.

To be sure, IMD only maintains long-term heatwave data for the Safdarjung station in the Capital. In May, Safdarjung had recorded six heatwave days — all in the second half of the month.