The wet spell over northern part of India, including Himachal Pradesh, Punjab and Haryana, will continue till May 6, bringing a drop in day temperatures.A fresh western disturbance is likely to bring light rain at isolated places in Punjab and Haryana on May 2, 3, 6 and 7, and at a few places on May 4 and 5, according to a bulletin issued by the India Meteorological Department (IMD) on Friday.A rise in day temperature by 2°C is likely in Haryana and Punjab over the next 48 hours and a fall by 3-4 degrees is expected thereafter. Thunderstorms and lightning along with gusty winds are also expected during this period.However, the foothills of Himalayas, which include states like Uttarakhand, Himachal Pradesh, Jammu and Kashmir, and east-coast states, including West Bengal, Odisha, Andhra Pradesh, and Tamil Nadu, will witness above normal heatwave days apart from states like Gujarat and Maharashtra.IMD Director General Mrutyunjay Mohapatra said the monsoon might arrive over the Andaman and Nicobar Islands around May 14-16. Several parts of the country will witness normal to above-normal rainfall except some parts of east and northeast India and east central India where rainfall will be below normal.The IMD also forecast favourable conditions for harvesting and threshing of late rabi crops in north and northwest India. “Localised above-normal temperatures in parts of the southern peninsular, northeast and northwest India may induce heat stress during the reproductive stages (flowering and grain filling) of rice (summer/boro), maize, pulses (green gram and black gram) and vegetables, leading to poor grain setting and flower drop,” the IMD said.The rainfall over the country in April was 35 mm, said to be the 10th lowest since 2001. The average maximum temperature in April was 35.13°C and average minimum temperature was 22.07°C. The western disturbances in April brought thunderstorms and rainfall mainly in the Western Himalayan region and north-east India.