Delhi bakes under warmest May night in 14 years, ‘poor’ air quality grips national capital

Delhi endured another scorching day on Thursday, as the city experienced its hottest May night in almost 14 years. Heatwave conditions continued for the fourth straight day in several areas.

The India Meteorological Department (IMD) reported that Safdarjung, Delhi’s primary weather station, recorded a minimum temperature of 31.9°C — 5.2 degrees above normal and 3.6 degrees higher than the previous day. Meanwhile, temperatures in some parts of the city remained above 45°C.

The last time Delhi recorded a higher minimum temperature in May was on 26 May 2012, when the mercury settled at 32.5 degrees Celsius, according to IMD data.

IMD issues Orange Alert for Friday

For Friday, the weather department issued an orange alert for the city, forecasting a minimum temperature of 32°C and a maximum of 44°C, along with heatwave conditions.

An official said the heatwave is likely to persist for the next week and advised residents to stay cautious, as the extended dry spell and extreme temperatures could greatly raise the risk of heat-related illnesses and sunstroke.

Safdarjung and Lodi Road were among the stations that recorded warm night conditions, the weather office said, as reported by PTI.

A warm night is declared when the maximum temperature remains 40 degrees Celsius or more and the minimum temperature departure is between 4.5 and 6.4 degrees Celsius above normal, according to the IMD.

Heatwave conditions prevailed across several parts of Delhi, marking the fourth straight day the national capital has experienced such extreme weather.

No respite from heat, says IMD

According to the IMD, the heatwave is expected to persist in Delhi over the next seven days due to dry northwesterly and westerly winds in the lower troposphere, along with the absence of any western disturbance impacting the plains of northwest India.

Safdarjung recorded a maximum temperature of 43.6 degrees Celsius, 3.4 degrees above normal and 0.9 degrees below the previous day's.

With 45.3 degrees Celsius, Ridge recorded the highest maximum temperature in the city, 3.1 notches above normal, while Ayanagar recorded 44.5 degrees Celsius, 2.2 notches above normal and 0.5 degrees lower than the previous day.

Palam logged a maximum temperature of 44.3 degrees Celsius, 3.6 degrees above normal, with a 24-hour decline of 0.6 degrees, while Lodi Road recorded 44.3 degrees Celsius, 5.3 degrees above normal and 0.3 degrees lower than the previous day.

On the minimum temperature front, Palam recorded 30.5 degrees Celsius, 3.4 notches above normal and two degrees higher than the previous day, while Ridge recorded 30.6 degrees Celsius, 4.4 notches above normal with a 24-hour rise of 2.6 degrees.

Lodi Road registered a minimum temperature of 29.6 degrees Celsius, 4.6 degrees above normal and 2.8 degrees higher than the previous day, while Ayanagar recorded 27.4 degrees Celsius, 0.7 degrees above normal with a rise of 0.4 degrees.

What is a heatwave? IMD says…

According to the IMD, a heatwave is observed when the maximum temperature crosses 40 degrees Celsius and remains 4.5 to 6.4 degrees above normal.

"Heatwave conditions are expected to continue for the next week. The northwesterly winds have been sweeping into the national capital from the Thar Desert region of Rajasthan and parts of central Pakistan for the past few days. Travelling across vast arid stretches, these winds turn intensely dry by the time they reach Delhi, trapping heat close to the surface and sharply intensifying the searing conditions across the city," said Mahesh Palawat of Skymet Weather.

Palawat said night temperatures have remained high over the last few days due to intense daytime heating.

Air quality deteriorates

“The ground does not get sufficient time to release the accumulated heat, leading to persistently warm nights. There is no forecast of thunderstorms or pre-monsoon rainfall over the next 10 days, which further worsens the situation. These dry northwesterly winds are also preventing any significant cooling and are trapping large amounts of heat,” he said.

Palawat added that the prevailing conditions are likely to persist over the coming days, pushing several parts of Delhi-NCR into heatwave conditions.

He also said the city's air quality has deteriorated due to dust-laden northwesterly winds and extremely dry conditions, resulting in higher PM10 concentrations.

Meanwhile, Delhi's air quality was recorded in the "poor" category with an AQI of 209.

According to the Central Pollution Control Board (CPCB), an AQI between zero and 50 is considered "good", 51 to 100 "satisfactory", 101 to 200 "moderate", 201 to 300 "poor", 301 to 400 "very poor", and 401 to 500 “severe”.