Night temperature to be above normal, IMD forecasts more heatwave days in May

New Delhi: Night temperature will be “above normal” in most parts of India this month while 4-5 additional heat wave days are likely along the east coast, Gujarat and Maharashtra, the India Meteorological Department said here on Friday, presenting the weather outlook for May.

Barring a few pockets in central and north-west India, the night temperature will remain high across the country. The day temperature, on the other hand, will stay “below normal” in most states barring the southern ones, north east India, Gujarat, Ladakh and eastern Uttar Pradesh.

“Nights are turning warmer because of the climate change whose impacts are more prominent on night temperature. Also when rain is expected, the nights become warmer due to the clouds that prevent heat release,” said Mrutyunjay Mohapatra, director general meteorology at IMD.

Gujarat, Maharashtra, almost the entire east coast, West Bengal, southern Himachal Pradesh and parts of Uttarakhand are likely to experience 4-5 additional heatwave days compared to the number of heatwave days they face every year. Temperatures may be 3-5 degrees Celsius above normal in those days.

In addition, Gujarat, peninsular states and north east India will be having above-normal day and night temperatures, giving little window to the residents to escape from the heat.

The IMD declares a heatwave when the maximum temperature reaches 40 degrees Celsius in the plains, 30 degrees Celsius in hilly areas and 37 degrees Celsius in coastal areas, with a departure from the normal maximum temperature of at least 4-5 degrees Celsius.

Also when the maximum temperature touches 45 degrees Celsius or goes beyond it, a heatwave is declared. Scientific studies have shown that the number of heatwave days are going to increase in India.

For those living in north west India, a little respite is expected this week because of an upcoming Western Disturbance that will be active between May 2-May 6. Thunderstorms may also occur in the east, north east and peninsular India.

Mohapatra said El Nino – an unusual warming of the Pacific Ocean impacting weather around the world – would develop by July influencing the south west monsoon. The monsoon winds are likely to prevail over the Andaman sea by the third week of May.

Fairly widespread to widespread rainfall along with thunderstorm, lightning and gusty winds (40-60 km per hour) with heavy to very heavy rainfall is likely over Sub Himalayan West Bengal & Sikkim and north-east India in this week.