New Delhi: The city on Monday recorded the season's second warmest night, with the minimum temperature rising to 32.4 degrees Celsius, which is 5.7 degrees above normal. This marked the highest minimum temperature for May in 14 years.
Dust Intrusion Worsens Air Quality
The intrusion of dust worsened Delhi's air quality, resulting in a haze over the city. At 4 pm, when the Central Pollution Control Board releases its 24-hour average Air Quality Index (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 8 pm. An official stated that dust-raising winds led to the rise in AQI.
Historical Context
According to the India Meteorological Department (IMD), 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.
Forecast for Tuesday and Wednesday
Warm night conditions are likely to prevail on Tuesday, with the minimum temperature expected to remain between 40 and 42 degrees Celsius. The Met department defines a 'warm night' when the maximum temperature exceeds 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, three degrees above normal. However, no heatwave condition was observed in the city. 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.
Definition of Heatwave
IMD defines a heatwave day when the maximum temperature is 4.5 degrees or more above normal and the maximum is at least 40 degrees Celsius. A heatwave is also considered if the maximum temperature touches 45 degrees Celsius or above.
Previous Heatwave Spells
This season, the city has experienced two spells of heatwaves. Parts of Delhi reeled under three consecutive heatwave days from April 23 to 25. Safdarjung recorded one heatwave day on April 25, when the mercury climbed to 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.
Relief Expected from May 28
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 60 kmph between May 28 and 31. “No large change in maximum temperatures till May 27 and fall by 7-8 degrees Celsius thereafter,” said an IMD official.
