The weather department on Wednesday extended its forecast of heatwave conditions over north-western India by another day, while also predicting rain over parts of Punjab, Haryana and Chandigarh subsequently, which is expected to bring relief by lowering daytime temperatures.Heatwave and warm night conditions are likely to continue till April 25, with light rain along with thunderstorms, lightning and gusty winds expected between April 26 and 28. On Tuesday, the India Meteorological Department (IMD) had forecast heatwave conditions till April 24 and rain on April 26 and 27.Over the past 24 hours, the highest maximum temperature recorded in Punjab was 41.6 degrees Celsius at Bathinda, while the lowest minimum temperature was 17 degrees Celsius at Adampur.In Haryana, the highest maximum temperature during this period was 42.5 degrees Celsius at Bhiwani, while the lowest minimum temperature was 19.9 degrees Celsius at Karnal.The IMD expects a gradual rise in maximum temperature by 3-4 degrees during the next four days in both the states and a gradual fall by about 2-3 degrees on April 27 and 28.Day temperatures were above normal in both Punjab and Haryana while night temperatures were above normal in Punjab. The weather in both the states remained dry, according to a bulletin issued by IMD on April 22.The seasonal rains from March 1 till April 22 have been above the long period average by 33 per cent in Haryana and 27 per cent in Punjab.A fresh western disturbance in middle tropospheric westerlies with its axis at 5,800 meters above mean sea prevails over Iran, while an upper air cyclonic circulation lies over southwest Rajasthan and adjoining Pakistan at 900 meters above mean sea.Under the influence of these weather conditions, isolated to scattered light to moderate rain or snow with thunderstorm, lightning and gusty winds is likely over Jammu and Kashmir, Ladakh and Uttarakhand on April 24 and 25, and over Himachal Pradesh during April 25-28.