New Delhi: Many parts of the country may not be warmer than normal due to ‘above normal’ rainfall this month, but some states, especially the Himalayan foothills like southern Himachal and Uttarakhand, the east coast and parts of Maharashtra and Gujarat, are likely to face ‘above normal’ heatwave days (additional 3 to 8 days), according to the IMD’s May forecast released on Friday.The weather department has also predicted warm nights (above normal minimum temperatures) in many parts of the country, with IMD chief Mrityunjay Mohapatra saying the phenomenon is linked to climate change.The ‘above normal’ rainfall during the month is attributed to the favorable trough and increased frequency of western disturbances and thunderstorms due to upper air cyclonic circulation. Due to this, the day temperature is likely to be ‘below normal’ in some areas.

“Maximum (day) temperatures are expected to be below normal to normal over many parts of the country. However, temperatures are likely to be above normal over many parts of southern peninsular India, parts of north-east and northwest India,” Mohapatra said.On the other hand, minimum (night) temperatures are expected to be above normal in many parts of the country, he said. “However, minimum temperatures are likely to remain below normal over parts of Central India and adjoining areas of Peninsular India and southern parts of Northeast India as well as many areas of Northwest India.”The southwest monsoon is expected to reach Andaman and Nicobar Islands around May 14-20. Its arrival in Kerala, which marks the arrival of monsoon over mainland India, is expected to be around May 15.The weather service has already predicted ‘below normal’ monsoon rainfall this year amid the threat of El Nino, an increase in sea surface temperatures over the central and eastern equatorial Pacific that is often associated with reduced rainfall over the Indian subcontinent.The increasing frequency of WDs – moist air and low pressure systems in the Mediterranean region that enter India and affect local weather – led to seven such events in April, causing thunderstorms, rain, winds and lightning over northwest and adjoining central and eastern India.Extreme weather events linked to WD killed 24 people last month. Lightning alone killed 10 people in Andhra, UP, Maharashtra and Odisha.