Heatwave Back In Delhi, North-West India To Scorch Till Thursday: All You Need To Know

Following a brief respite, several parts of north west India are set to witness some more days of scorching heat with weather forecasters predicting heatwave conditions likely to last till Thursday.

What's causing the heatwave? 

Temperatures had dropped over north-west and central India under the influence of easterly winds and a western disturbance from May 21-31. According to weather scientists, heatwave conditions are likely to prevail again due to the influence of dry and warm westerlies blowing from the direction of Pakistan.

"Since May 31 to June 2, the impact of easterlies at the lower level decreased and there has been increasing dry and warmer westerly from the direction of Pakistan, making areas of northwest and central India further dry and also warmer," a senior IMD official said.

The India Meteorological Department (IMD) uses four colour codes for weather warnings -- "green" (no action needed), "yellow" (watch and stay updated), "orange" (be prepared) and "red" (take action). 

A heatwave is declared when the maximum temperature is over 40 degrees Celsius and at least 4.5 notches above normal. A severe heatwave is declared if the departure from normal temperature is by more than 6.4 notches, according to the IMD. Based on the absolute recorded temperatures, a heatwave is declared when an area logs a maximum temperature of 45 degrees Celsius. A severe heatwave is declared if the maximum temperature crosses the 47-degree Celsius mark.

Here are some states where heatwave conditions have been and are likely to be the most severe this time:

Delhi

The IMD has issued an orange alert for Delhi and neighbouring areas. The ongoing heatwave spell tightened its grip on parts of Delhi on Sunday, with the mercury breaching the 45-degree Celsius mark in six localities. At the Safdarjung Observatory, the city's base station, the maximum temperature settled at 44.2 degrees Celsius as against 43.9 degrees Celsius on Saturday and 42.9 degrees Celsius on Friday. The mercury jumped to 47.3 degrees, seven notches above normal, at Mungeshpur, making it the hottest place in the capital.

Sports Complex, Pitampura, Najafgarh, Jafarpur and Ridge recorded a high of 46.6 degrees Celsius, 46.2 degrees Celsius, 46.3 degrees Celsius, 45.1 degrees Celsius and 45.7 degrees Celsius respectively. The Met office has issued a "yellow" alert, warning of heatwave conditions at isolated places in Delhi on Monday. 

Mahesh Palawat, vice-president (climate change and meteorology), Skymet Weather, said Delhi, Haryana, Punjab, north Rajasthan and west Uttar Pradesh may see pre-monsoon activity on and off from June 10. The maximum temperature in the capital may drop to 40-41 degrees Celsius by Saturday.

On Tuesday, the minimum temperature rose slightly in the city to settle at 27.6 degrees Celsius, even as the weather office forecast strong surface winds later in the day. The maximum temperature is expected to rise to 44 degrees Celsius, with no respite from the sweltering heat in the city.

Rajasthan

Heatwave conditions persisted in parts of Rajasthan on Monday, with Sri Ganganagar being the hottest place in the state with a maximum temperature of 46.3 degrees Celsius. Cloudy skies and strong winds helped bring down the mercury by one to two notches, a meteorological department spokesperson said.

Sangaria recorded a maximum temperature of 45.6 degrees Celsius, followed by 45.3 degrees Celsius in Churu, 45.2 degrees Celsius in Pilani, 45 degrees Celsius each in Bikaner and Alwar, 44.8 degrees Celsius each in Barmer and Dholpur, 44.7 degrees Celsius in Jaisalmer, 44.3 degrees Celsius in Anta, and 44.1 degrees Celsius in Chittorgarh. Jaipur recorded a high of 40.8 degrees Celsius.The minimum temperature in all major cities was recorded between 25 degrees Celsius and 32 degrees Celsius on Sunday night.

The weather department has forecast severe heatwave conditions in Sri Ganganagar on Tuesday.

Other states

Heatwave conditions are likely to prevail over Punjab, Uttarakhand, Haryana and Delhi till Thursday, the India Meteorological Department (IMD) said. On Monday, Banda and Fatehgarh in Uttar Pradesh were the hottest places in the country as they recorded the highest maximum temperatures of 46.8 degrees Celsius and 46.4 degrees Celsius respectively. The mercury touched a maximum of 46.3 degrees in Rajasthan's Sriganganagar, while Khajuraho and Nowgong in Madhya Pradesh sizzled at 46 degrees Celsius.

The weather office has forecast heatwave conditions over Odisha, Uttar Pradesh, Madhya Pradesh, Jammu division, Himachal Pradesh, Vidarbha and north Jharkhand for the next two days.

Heavy Rain In North-East And Other Parts

While heatwave persists in northwest India, other states are likely to get rainfall in the coming days. Under the influence of strong southwesterly winds from the Bay of Bengal to northeast India, widespread rainfall is very likely over Arunachal Pradesh, Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, sub-Himalayan West Bengal and Sikkim for the next five days.

The weatherman has also forecast fairly widespread rainfall with thunderstorm and lightning over Karnataka, Kerala, Mahe and Lakshadweep, and scattered rains over Andhra Pradesh, Tamil Nadu and Puducherry over the next five days under the influence of westerly winds from the Arabian Sea over peninsular India.

The south-west monsoon, which reached Kerala on May 29, has entered a weak phase and is expected to pick up pace from Tuesday and advance further.

(With inputs from PTI)