Severe heatwave in Delhi as mercury jumps to 41.6°C

The maximum temperature at Safdarjung observatory, considered Delhi’s official base weather station, on Friday was seven degrees above normal and 1.6 degrees higher than the previous day’s 40°C, when the Capital reported its first official heatwave of this year

Severe heatwave conditions prevailed across Delhi on Friday as the maximum temperature touched the year’s high of 41.6 degrees Celsius (°C), following which IMD issued an “orange alert” for Saturday, when the temperature is expected to rise to 42°C.

Near Delhi University, on Friday. (Amal KS/HT)

The maximum temperature at Safdarjung observatory, considered Delhi’s official base weather station, on Friday was seven degrees above normal and 1.6 degrees higher than the previous day’s 40°C, when the Capital reported its first official heatwave of this year.

IMD said this is the quickest rise to 41.6°C in April since 1951. Previously, in 2010, the temperature touched 41.6°C on April 12.

IMD said this is the quickest rise to 41.6°C in April since 1951. Previously, in 2010, the temperature touched 41.6°C on April 12.

A heatwave is when the maximum temperature is over 40°C and 4.5 degrees above normal, and a severe heatwave is when the temperature is above 40°C and 6.5 degrees above normal. While some parts of Delhi were recording what could classify as heatwave and severe heatwave conditions for the last two weeks, the temperature at Safdarjung touched 40°C, a prerequisite to declare a heatwave or severe heatwave, only on Thursday.

On Friday, the temperature rose above 40°C at all weather stations across the Capital, with the highest -- 43.9°C -- recorded at the Yamuna Sports Complex in east Delhi. Severe heatwave readings were also recorded at Pitampura (43.4°C), Mungeshpur (43°C), Ridge (42.9°C), Aya Nagar (42.4°C) and Lodhi Road (41.9°C) stations.

IMD senior scientist RK Jenamani said that the IMD issues warnings after considering an event’s probability and impact. “When the probability is high and the impact is fatal, with temperature in the 44-46°C range, we go for a red warning. If the temperature is between 41°C and 43°C, we go for the orange alert, but the chances for occurrence should be above 60%,” said Jenamani, adding that the severity of the heat may drop from April 12 due to a possible cloud cover.

Earlier this week, IMD had declared a “yellow alert” -- issued to warn the public of a weather event taking place -- in the city till April 13, but the weather body stepping up the warning level to “orange” for Saturday. The IMD uses four colour codes — green, yellow, orange and red -- to warn of severely bad weather.

Across the country

Meanwhile, Met department has predicted prevalence of heat wave and severe heat wave conditions in isolated pockets over Punjab, south Haryana-Delhi areas during the next five days; over west Uttar Pradesh in the next three days; and over Gujarat on Friday and Saturday.

On Thursday, the maximum temperature ranged from 42-44°C in most parts over west Rajasthan, parts of southeast Uttar Pradesh, west Madhya Pradesh, Saurashtra-Kutch and Vidarbha; and from 41-43°C in most parts of east Rajasthan, east Madhya Pradesh, and in the remaining parts of east Uttar Pradesh; Jharkhand, Gujarat, south Haryana, Delhi, Madhya Maharashtra and Marathawada.

Maximum temperatures were above normal by 6-10 degrees in many parts of the Jammu division and Himachal Pradesh; and by 4-6 degrees in many parts of Uttarakhand, Punjab, Rajasthan, Haryana-Delhi and in isolated pockets over Madhya Pradesh, east Uttar Pradesh and Saurashtra-Kutch.

There is a 48% deficiency of rainfall across the country, with shortfall rising to 91% in northwest India, 83% over central India, 19% over southern peninsula and 1% over east and northeast India.

“A feeble low-pressure area is likely to form but conditions are not favourable for its intensification. Vertical wind shear over Bay of Bengal is increasing which will not allow it to intensify. The impact of low-pressure area will mainly be on Tamil Nadu and Kerala. This means that heat wave conditions over northwest India will not abate now. The anti-cyclone over Rajasthan has moved towards northwest Arabian Sea. This will lead to hot, dry westerly winds from Baluchistan, central Pakistan and Thar desert affecting northwest India for at least the next four-five days. Later, around April 13 or 14, a trough is likely to form which may increase humidity levels and trigger some pre-monsoon showers. We have to wait and watch,” said Mahesh Palawat, vice-president, climate and meteorology, Skymet Weather.