Heatwaves surge across India. Weather office says will get hotter in next 5 days
IMD, or India Meteorological Department said people can expect some relief only from May 2 when the maximum temperature may drop to 37-38°C over parts of northwest India.
Delhi recorded a maximum temperature of 43.5 degrees Celsius on Thursday, the highest April temperature in 12 years as a heatwave continued to rage across vast swathes of India. Prayagraj, in Uttar Pradesh was the hottest city in the country on Thursday, with a maximum of 45.9 degrees Celsius.
The India Meteorological Department (IMD) warned that the heatwave will become more intense over the next five days, with temperatures likely to touch 45 degrees Celsius (°C) in some parts of the country.
Behind the heatwave is a so-called anti-cyclone, which is expected to last till early next week. “The heatwave is mainly because of a strong anti-cyclone over the north Arabian Sea which is bringing hot, westerly winds. There is likely to be relief from May 2 because we are expecting a strong western disturbance (a cyclonic movement). Maximum temperatures will drop to 37-38°C over parts of northwest India,” said R K Jenamani , senior scientist, national weather forecasting centre, IMD.
But until then, many parts of the country will continue to swelter under hot and dry conditions.
According to IMD’s gridded dataset, the average maximum temperature till April 27 was 35.7 degrees Celsius, the highest in five years for this month. However, this headline number hides just how hot northwest India has been. In four states – Madhya Pradesh, Rajasthan, Punjab, and Gujarat – the average maximum temperature in April 2022 so far has been the highest since 1951; while it has been the second highest in Delhi (including neighbouring districts), Uttar Pradesh, and Haryana.
And many parts of the country have seen no rain in April. Rainfall in April so far in states like Punjab, Haryana, Madhya Pradesh, Uttar Pradesh, Uttarakhand, Jharkhand, and Telangana is in the bottom 20 since 1901, according to IMD’s gridded dataset. However, average rainfall till April 27 across India was 44.23mm, 19th highest since 1901, largely due to rainfall in north-eastern and some southern states.
Things will only get worse between Friday and Monday. Delhi, for instance, may see the mercury cross 44°C on Friday.
IMD has issued an orange alert for Rajasthan on April 28 and 29 and a yellow alert for almost the entire country except parts of peninsular and east India. An orange alert is a warning to administrators to be prepared for imminent heat waves; a yellow alert is to warn them to be watchful.
For April 30, May 1 and 2, IMD has issued an orange alert for Madhya Pradesh, Maharashtra and Chhattisgarh and a yellow alert for the rest of the country except the peninsular region.
According to IMD, maximum temperatures will increase by 2°C across most parts of northwest India on April 29 and 30, and fall only after May 2. The weather office added that maximum temperatures over east India will stay at current levels for the next few days and fall by about 2-3°C thereafter.
During an anti-cyclone, air pressure is high on the surface, causing the air above it to come down. This air warms up as it comes down on account of high pressure. The outward hot winds caused by this are ranging as far as Odisha and West Bengal.
But early next week, the western disturbance (a cyclonic movement originating in the Mediterranean) will put an end to the anti-cyclone, cause moisiture laden winds to come in from both the Arabian Sea and the Bay of Bengal. These easterly winds will reduce temperatures to 37-38 degree C over parts of northwest India, Jenamani explained.
Maximum temperatures are currently 43-45°C over many parts of northwest India.
Prayagraj was the hottest city in the country on Thursday, followed by Daltonganj in Jharkhand, and Chandrapur in Maharashtra, where the maximum temperature touched 45.8°C on Thursday. In Ganganagar in Rajasthan, the maximum touched 45.7°C on Thursday, and closely followed by Gurugram, Khajuraho (Madhya Pradesh), Jalgaon (Maharashtra), and Agra (Uttar Pradesh), all which saw the mercury soar to 45.6°C.
Temperature in the desert regions of Rajasthan ranged between 43 to 45.2°C. In Uttar Pradesh, Varanasi saw a maximum of 44.5°C, while Sultanpur saw the highest temperature of 44.2°C. In Maharashtra, the temperature in Akola touched 45.4°C, while in Brahmapuri it soared to 45.1°C, and was 45°C in Wardha. In neighbouring Gujarat, Amreli and Bhuj recorded highest temperatures of 43.2°C. Jharsugunda in Odisha recorded 44°C, whereas Dhenkenal in saw 43.1°C. Bishnupur in West Bengal recorded 42.7°C.
With the heat wave soaring, several states have announced early summer vacations in schools to shield children from the intense heat. Chhattisgarh has closed schools since April 24, and Odisha has declared special heat wave holiday from April 26 to April 30. Schools in Bhopal in Madhya Pradesh have been shut from April 29 and in Andhra Pradesh schools will be shut from May 6. States such as Rajasthan have announced water trains for districts such as Pali and Jaisalmer to cope with drinking water shortages.
“The heatwave will impact a very large area of the country compared to the heatwave in March. This spell will also be very intense. Maximum temperatures are already in the mid 40s in many parts and may rise further. We can expect an intense spell over Punjab, Haryana, parts of UP, Madhya Pradesh, Delhi etc. There may be some dust storm activity over Rajasthan because many parts of Rajasthan are facing a very prolonged dry spell. The heat wave over east India especially Odisha and West Bengal may subside from April 30,” said Jenamani.
IMD has warned that the heat wave could lead to moderate health concerns for vulnerable people including infants, the elderly, and people with chronic diseases. There is also an increased likelihood of heat illness symptoms in people who are either exposed to sun for a prolonged period or doing heavy work, it added. IMD has also recommended that people should avoid heat exposure– keep cool; avoid dehydration by drinking sufficient water even if not thirsty; avoid heat exposure, wear lightweight, light-coloured, loose, cotton clothes and cover the head; and drink oral rehydration salts, and home-made drinks.
Extreme heat stress over large parts of India has triggered a discussion on heatwave spells.
Several research papers in the past have flagged India’s vulnerability to heat extremes. A 2016 paper by the Indian Institute of Tropical Meteorology and IMD said the frequency, total duration and maximum duration of heatwaves are increasing over central and northwestern parts of the country, The warming of the tropical Indian Ocean and more frequent El Nino events in future may further lead to more frequent and longer lasting heat waves over India, it added.
Another paper published in Springer in 2019 said there is likely to be an increase of about two heat waves and 12–18 days in heatwave duration during the period 2020–2064 in a moderate global emissions scenario. “In the future climate change scenario, southern parts of India and coastal parts of India which are presently unaffected by heat waves, are likely to be affected by heat waves,” it added.
“The anti-cyclone is leading to incursion of hot, dry winds over a very large area up to east India. The soil is also very dry. There has been no rain. So, the conditions are extreme. A very interesting and concerning thing to note is that the heat waves have impacted West Bengal this time. Again, we didn’t expect that. That’s not a text-book heat wave prone region. Coastal Odisha and Andhra are heatwave prone because of local factors. This shows that the area impacted by extreme heat is increasing,” said M Rajeevan, former secretary, ministry of earth sciences.
“We need to create awareness and take action. Heat waves are deadly. They will kill people working outdoors like farm labourers, construction workers. In most cases they just collapse. Heat wave intensity and duration will only increase in coming years,” added Rajeevan.
“The extreme heat wave hitting India this week comes on top of 1°C warming that country has already experienced. However, on our current emissions trajectory (SSP2-4.5) India is headed for around 3.5°C warming by the end of the century,” tweeted Zeke Hausfather, climate scientist and an author of the Intergovernmental Panel on Climate Change report.