New Delhi, April 18 : After a brief respite over the weekend, the maximum temperature in Delhi is likely to soar up to 42 degrees Celsius on Monday, the India Meteorological Department. The minimum temperature was recorded at 22.5 degrees Celsius, one notch higher than the season’s normal. “Heatwave conditions in isolated pockets are very likely to prevail over Punjab, Haryana-Delhi, south Uttar Pradesh, Rajasthan, Bihar, Odisha and Jharkhand during April 18 and19,” the IMD bulletin said. “The sky will remain partly cloudy sky with possibility of development of thunder, lightning on April 20 and 21,” it added. The relative humidity in the city at 8.30 am was 52 per cent. The Air Quality Index (AQI) around 9 am was 252, according to data recorded by the System of Air Quality and Weather Forecasting And Research, which is seen as “poor”. Along with Delhi, heatwave conditions will remain in Haryana, Punjab and Rajasthan till Tuesday. JA ING