New Delhi: The city continued to swelter in extreme heat on Sunday. A marginal drop in the maximum temperature did not bring comfort, while a nighttime temperature of 26.2°C did not promise relief either.The only relief, that too on paper, is that Delhi did not record a heatwave anywhere on Sunday after three days of back-to-back heatwaves.Safdarjung logged a maximum of 42.1°C — 3 degrees above normal. It was 42.8°C on Saturday, Delhi’s hottest April day in four years.The highest maximum across the city was 43.5°C at the Ridge. It was 44.5°C on Saturday when Delhi had its first citywide heatwave. Prior to that, Delhi saw heatwave conditions in isolated pockets on Thursday and Friday.The IMD has sounded a yellow alert for isolated heatwave conditions on Monday too, with chances of a scattered drizzle to light rain post-noon.Relief is likely on Tuesday and Wednesday, with scattered rain and strong winds leading to a marginal cooling effect. The mercury could dip below 40°C.The IMD announces a heatwave when the maximum temperature is at least 4.5 degrees above normal and above 40°C. A heatwave is also declared if the maximum is 45°C or more. No station met the criteria on Sunday, while four stations, including Safdarjung, were meeting it on Saturday.“In Delhi, maximum temperatures were observed in the range of 42-44°C on Sunday, yet no heatwave conditions have been observed due to a slight fall of 1°C in the maximum temperature and close to a 1°C rise in the normal temperature,” said IMD officials.“Normal temperatures change after a five-day interval and are called Pentad Normals. The normal temperature for Safdarjung for the period April 26-30 is 39°C, while it was 37.7°C for the period April 21-25,” officials added.Initially, the Met had issued an orange alert for Delhi, forecasting the maximum to be between 43°C and 45°C. Forecasts show a maximum of 43-45°C is likely on Monday, but with overcast skies and rain returning, it is expected to be between 40-42°C on Tuesday and dip further to 39-41°C on Wednesday. “The cloudiness is expected to remain on Thursday too, by which time the maximum may fall to close to 37°C,” another IMD official said.On Sunday, the minimum was 26.2°C, 2 notches above normal and the warmest this month.Last year, the highest minimum temperature recorded in April was 27.2°C, and prior to this it was in April 2019 that the highest minimum went to 27.1°C, making 26.2 degrees Celsius recorded on Sunday the second highest for April since 2019.Nights will continue to stay warm, with the minimum hovering between 26-28°C on Monday and between 27-29°C on Tuesday.The AQI was 222 (poor) on Sunday, a marginal improvement from 243 on Saturday.The Air Quality Early Warning System for Delhi says AQI is likely to be poor till Monday, before improving to moderate on Tuesday.