Delhi sets heatwave record on hottest April day in 5 years

The five heatwave days are the most for the month since 2017, when April recorded six days when the maximum temperature was high enough for it to be classified a heatwave.

Delhi recorded its fifth consecutive heatwave day on Monday with the Safdarjung observatory, the Capital’s base station for weather, recording a maximum temperature of 42.6 degrees Celsius (°C), seven degrees above normal, making it the hottest April day since 2017 when it touched 43.2°C on April 21.

Monday’s high of 42.6°C has eclipsed Saturday’s maximum temperature of 42.4°C, which was also the highest recorded in the first half of April in the last 72 years. (Rahul Raut/HT file photo)

The five heatwave days are the most for the month since 2017, when April recorded six days when the maximum temperature was high enough for it to be classified a heatwave. With close to three weeks to go, this record is likely to be broken, especially with the India Meteorological Department (IMD) forecasting a short-lived, mild window of relief.

“We expect mercury to drop to around 40 degrees on Tuesday owing to partly cloudy skies in parts of Delhi. This will reduce the impact of the heat somewhat. On Wednesday and Thursday, it will be around 39 degrees, before it begins to rise once again from Friday onwards,” said IMD scientist RK Jenamani, adding that Delhi is likely to end the weekend around 41°C again.

The brief respite will be due to a western disturbance over northwest India. “This will bring clouds over Delhi, that can bring down the maximum temperature by 1-2 degrees over most places. Delhi so far had clear skies which allowed temperatures to rise quicker,” Jenamani said, adding that there will be no rain.

IMD, which had issued an “orange” alert for Monday, has downgraded it to “yellow” for Tuesday and “green” for Wednesday and Thursday.

According to IMD, Saturday’s maximum temperature of 42.4°C was also the highest recorded in the first half of April in the last 72 years, between 1951 and 2022. Monday’s high of 42.6°C has now eclipsed this record too.

This year has been unusually hot with no western disturbance to hit the region since February-end. Typically, 10-12 spells are recorded between February and April, with most bringing pre-monsoon rain.

IMD issues a yellow alert to alert the general public about a weather phenomenon, and an orange alert urges people to take precautionary measures– in this case, to be prepared for a heatwave.

A heatwave is when the maximum temperature is above 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.

On Monday, the Yamuna Sports Complex station in east Delhi was the hottest location in Delhi, with mercury touching a high of 44.1°C.

The minimum temperature at Safdarjung was 22.5°C, two degrees above normal.

Delhi touched 40°C for the first time on Thursday, subsequently rising to 41.6°C on Friday and 42.4°C on Saturday before dipping slightly to 41.8°C on Sunday. The average normal temperature from April 6-10 is 34.7°C, and 36.1°C between April 11 and 15.

Last year, the highest maximum temperature recorded in April was 42.2°C, on April 29. In 2020, the highest was 40.1°C on April 16; and in 2019, it was 42.1°C on April 26. Since 2011, the highest maximum for April is 43.2°C, which was recorded on April 21, 2017. The all-time record for April is 45.6°C, recorded on April 29, 1941.

Forecast for Tuesday shows the temperature hovering between 40°C and 23°C at Safdarjung, with heatwave conditions expected in isolated parts of Delhi.