City records warmest night in 14 years, AQI in higher end of poor

New Delhi: The city on Monday recorded the season’s second warmest night, with the minimum temperature rising to 32.4 degrees Celsius, 5.7 degrees above normal. It was also the highest minimum temperature for May in 14 years.

The intrusion of dust worsened Delhi’s air quality, with a haze appearing over the city. At 4pm, when Central Pollution Control Board releases its 24-hour average AQI, the figure stood at 254 compared to 204 a day earlier. However, it later deteriorated to the higher end of the ‘poor’ range, reaching 281 at 8pm. An official said the dust-raising winds led to a rise in AQI.

According to India Meteorological Department, a higher minimum temperature in May was last recorded at 34.2 degrees Celsius on May 27, 2012. The city saw the season’s first warm night on May 21, when the mercury reached 31.9 degrees Celsius.

Warm night conditions are likely to prevail on Tuesday as the minimum temperature is expected to remain between 40 and 42 degrees Celsius.

The Met department considers a ‘warm night’ when the maximum temperature is over 40 degrees Celsius and the departure of minimum temperature is 4.5 degrees Celsius or more above normal.

On Monday, the maximum temperature was recorded at 43.5 degrees Celsius on Monday, three degrees above normal. However, no heatwave condition was seen in the city. However, heatwave conditions are likely to return on Tuesday and Wednesday.

“The day temperature is expected to stay around 43-45 degrees Celsius on Tuesday and Wednesday, with heatwave conditions likely in isolated areas. Even warm night conditions are likely on Tuesday,” said a Met official.

IMD defines a heatwave day when the maximum is 4.5 degrees and more above normal temperature and the maximum is at least 40 degrees Celsius. A heatwave is also considered if maximum temperature touches 45 degrees Celsius or above.

This season, the city has seen two spells of heatwaves. Parts of Delhi reeled under three consecutive heatwave days from April 23 to 25. Safdarjung saw one heatwave day on April 25, when the mercury climbed 42.8 degrees Celsius. The second four-day streak of heatwave conditions was recorded from May 18 to 21. However, Safdarjung recorded just one such day on May 19 when it touched 45.1 degrees Celsius.

Heatwave conditions are likely to abate from May 28. IMD has predicted a spell of light to very light rain accompanied by thunderstorms and gusty winds up to 60kmph between May 28 and 31. “No large change in maximum temperatures till May 27 and fall by 7-8 degrees Celsius thereafter (sic),” said an IMD official.