As monsoon plays truant, Delhi suffers first heat wave of season

IMD recordings showed that the maximum temperature at the Safdarjung observatory, which is considered the official marker for the city, was 43 degrees Celsius, six degrees above what is considered normal for this time of the year. The minimum temperature was 27.4 degrees Celsius, a notch below normal.

The maximum temperature in Delhi on Tuesday touched 43 degrees Celsius, which was the highest recording this year, with the India Meteorological Department (IMD) classifying it as the first heatwave day this season.

The IMD forecast said that such dry heat is likely to continue throughout the week. (Rahul Raut/HT file photo)

IMD recordings showed that the maximum temperature at the Safdarjung observatory, which is considered the official marker for the city, was 43 degrees Celsius, six degrees above what is considered normal for this time of the year. The minimum temperature was 27.4 degrees Celsius, a notch below normal.

In the plains, heatwave days are classified – when the maximum temperature crosses 40 degrees Celsius, and when the day temperature exceeds the region’s normal maximum temperature by 4.5 degrees Celsius. A severe heatwave is declared when there is a departure of 6.5 degrees Celsius or above from normal temperatures.

An IMD official said this was the first heatwave recording of the season and such high temperatures are generally not seen at this time of the year. “In the beginning and even till mid-June we have seen maximum temperatures in Delhi rise up to 48 degrees Celsius, but by end of June, temperatures tend to come down,” a senior IMD official said.

At the Palam observatory, the maximum temperature was 43 degrees Celsius and the minimum temperature was 28.2 degrees Celsius, and at Aya Nagar, the day time temperature rose to 43.2 degrees Celsius and the minimum temperature was recorded at 28.3 degrees Celsius. At the Najafgarh and Pitampura weather stations, the maximum temperatures were above 44 degrees Celsius.

Mahesh Palawat, vice-president (climate change and meteorology) at Skymet Weather, a private weather forecaster, said the reason behind such high temperatures in Delhi was the dry westerly winds blowing over the national capital.

“Generally, this time of the year, Delhi gets cool, humid, easterly winds but, currently, Delhi is receiving dry winds from the west and this is keeping the temperatures high,” Palawat said.

Another IMD official said the delay in monsoon over parts of northwest India, including Delhi, was another reason behind the high recordings.

Delhi has this year experienced a relatively cooler summer season, with temperatures during April, May and even till the second week of June recording lower than normal. However, the conditions changed over the last one week, with the temperatures rising above the 40 degrees mark.

In April, Delhi recorded the lowest minimum temperature in at least a decade, on April 4, at 11.7 degrees Celsius. May was also relatively cooler under the impact of cyclonic storm Tauktae, when the city on May 19-20 broke the record for the highest single-day rainfall for the month, with 119.3mm of rain. This also pushed the month’s rainfall in the city to 144.8 — the second highest in May since 2008.

Another cyclonic storm, Yaas, also led to gusty winds and intense showers continuing, which brought temperatures down, breaking the record of one of the lowest mean maximum temperatures to be recorded in the month of May. The streak of low temperatures continued in June, when the minimum temperature on June 1 was 17.9 degrees Celsius, the lowest to ever be recorded in the month.

Delhi appeared to be headed for an early monsoon this year, with IMD initially predicting its arrival on June 15, at least 12 days ahead of its usual arrival date of arrival on June 27. However, weather conditions changed since then and in subsequent forecasts, IMD officials said that the monsoon in Delhi was on “halt” and was unlikely to hit the region till at least the first week of July.

Even though IMD has refrained from announcing a fresh monsoon arrival date, Skymet’s Palawat on Tuesday said that looking at the current weather conditions, monsoon arrival in Delhi was unlikely before July 8.

The IMD forecast said that such dry heat is likely to continue throughout the week. On Friday, parts of the national capital are expected to receive light rain and thunderstorm, which may bring down the temperature by 1-2 degrees Celsius.

Because of the delay in monsoon arrival this year, Delhi has also been reeling under a rainfall deficit of almost 40%, according to IMD recordings. The normal rainfall mark for June is 65.5mm. Last year, however, Delhi recorded 81.8mm rainfall in June after the monsoon arrived on June 25, two days earlier than its usual date.