The India Meteorological Department (IMD) has issued a red alert for Delhi-NCR, warning of a ‘severe heatwave’ for the next three days, until May 29. The NCR (National Capital Region) typically comprises Ghaziabad, Faridabad, Gurugram, and Noida. However, Panipat, Bhiwani, Jhajjar, Jind, Hisar, Karnal, Meerut, Bijnaur, Palwal, Hodal, Hathin, Aligarh, Bulandshahar, Mathura, Nuh, Rewari, Alwar, and Narnaul are also a part of the region.
Delhi NCR has been witnessing extreme temperatures since late April. IMD’s data suggests that this year’s heat waves in April were far worse than last year’s, making it the warmest year on record.
IMD said heatwave to severe heatwave conditions are very likely in several parts of Rajasthan, Punjab, Haryana, and Chandigarh during the week. West Uttar Pradesh will experience a severe heatwave during the 2nd half of the week.
Heatwaves in other states
Heatwave conditions have also been predicted in isolated pockets of Jammu division, Himachal Pradesh, Madhya Pradesh, Vidarbha, and Uttar Pradesh till 27 May.
Heatwaves are a period of unusually high temperatures as compared to what is normally expected over a region, according to IMD. Therefore, the temperatures at which heatwaves are declared differ from place to place based on the temperature climatology (historical temperatures) of that region. Supportive meteorological factors, such as high humidity, high wind speed, and the duration of heatwave events, aggravate the impact of heat waves.
The threshold for a heatwave is met when the maximum temperature of a weather station reaches at least 40 degrees Celsius in the plains, 37 degrees in the coastal areas, and 30 degrees in the hilly regions, and the departure from normal is at least 4.5 notches. A severe heatwave is declared if the departure from normal exceeds 6.4 notches.
A group of leading climate scientists said similar heat waves could occur once every 30 years, and due to climate change, they have already become about 45 times more likely.
