Follow Us:
Tuesday, June 28, 2022

Explained: Why is Delhi sweltering, and can we expect any respite?

Delhi heatwave explained: The national capital region is in the midst of a third heatwave this summer. What's the forecast? Why have temperatures remained persistently high? Is this normal?

Written by Abhinaya Harigovind , Edited by Explained Desk | New Delhi |
Updated: April 29, 2022 1:27:30 pm
Delhi heatwave: The forecast for the Safdarjung weather observatory indicates that heatwave conditions are likely to persist on April 29 and 30, and May 2.. (Express Photo: Praveen Khanna)

Delhi-NCR is in the midst of another heatwave, with the maximum temperature at some weather observatories likely to hit 45 degree Celsius on Thursday. This is the third heatwave spell the city is witnessing this summer.

Delhi heatwave: What is the forecast?

Heatwave conditions remain on the forecast for the next five days in parts of Delhi, Haryana, Chandigarh, Punjab, Rajasthan, Madhya Pradesh, western Uttar Pradesh and Vidarbha.

In Delhi, the forecast for the Safdarjung weather observatory, which serves as a marker for the city, indicates that heatwave conditions are likely to persist on April 29 and 30, and May 2. The maximum temperature at Safdarjung is likely to be 43 degrees on Thursday, and could rise to 44 degrees Celsius on April 29 and 30.

A heatwave is recorded when the maximum temperature is 4.5 to 6.4 degrees above the normal and is 40 degrees Celsius or more in the plains. The conditions to register a heatwave may also be fulfilled if the maximum temperature is 45 degrees Celsius or more. The ‘normal’ for Delhi from April 26 to 30 is 38.6 degrees Celsius, which is a long period average.

Best of Express Premium
UPSC Key-June 28, 2022: Why to read ‘Hurting religious Sentiments’ or ‘In...Premium
Did NCP hold Uddhav hand, stop resignation, give him false hope?Premium
Record $82 billion dealmaking spree sees India defy global slumpPremium
How Rampur, Azamgarh were won: Behind BJP chipping away of SP votesPremium

Some respite from the sweltering heat is on the cards next week.

R K Jenamani, senior scientist, India Meteorological Department (IMD), said an active western disturbance could bring rainfall to northwest India from May 2 to 5, consequently bringing the maximum temperature down. The western disturbance along with easterly winds carrying moisture from the Bay of Bengal will provide favourable conditions for rainfall or thunderstorms, and “good respite” from the heat, he said.

Why have temperatures remained persistently high, and what’s different compared to previous years?

Higher than normal maximum temperatures were recorded early this summer, from the end of March onwards. The heatwave spells can be attributed to dry weather on account of dry westerly winds, Jenamani said. The city has mostly remained dry for around 65 days now, he added.

The first heatwave spell that Delhi and NCR witnessed began on March 27 and continued till the beginning of April, he explained. The second heatwave spell was around April 19 and 20, while the ongoing one is the third.

The Safdarjung weather station has recorded eight heatwave days in April. This is the second-highest number of heatwave days in April in a little over a decade, after 11 such days in April 2010. If the ongoing spell continues, the number of heatwave days in April this year could equal the number recorded in 2010.

“At the city observatory, we might record 10 or 11 heatwave days this month, which is likely to be equal to the number recorded in 2010,” Jenamani said.

The normal amount of rainfall at Safdarjung in April is 11.4 mm. In contrast, the station has recorded 0.3 mm. No rain was recorded in March, against a normal of 15.9 mm.

The highest maximum temperature recorded at the Safdarjung weather station so far this month is 42.6 degrees recorded on April 12 and 20. The all-time highest maximum temperature at Safdarjung in April is 45.6 degrees in 1941. The summer setting in earlier this year means that Delhi has already recorded the hottest day in the first half of April in 72 years.

As part of the ongoing heatwave spell, several parts of the country including parts of Odisha, Maharashtra and Rajasthan witnessed heatwave conditions on Wednesday as well.

Express Subscription Do not hit the wall, subscribe for the best coverage out of India starting at just $5 per month

📣 Join our Telegram channel (The Indian Express) for the latest news and updates

For all the latest Explained News, download Indian Express App.

  • Newsguard
  • The Indian Express website has been rated GREEN for its credibility and trustworthiness by Newsguard, a global service that rates news sources for their journalistic standards.
  • Newsguard
0 Comment(s) *
* The moderation of comments is automated and not cleared manually by