KARACHI: As Karachi sizzles at 40.2 degree Celsius, a heatwave sets in several cities of the province on Saturday — two days prior to the forecast of the Met department.

The hottest city in Sindh on Saturday was Shaheed Benazirabad where maximum temperature was 48.5°C.

While the Met Office had forecast that daytime temperatures were “likely to remain 4 to 6 degrees centigrade above normal” in Sindh and Punjab from May 21, the maximum temperature recorded in at least 12 cities of the province— Karachi, Hyderabad, Mirpurkhas, Shaheed Benazirabad, Dadu, Jacobabad, Sakrand, Padidan, Chhor, Mithi, Thatta and Tandojam — already surged to three to four degrees Celsius above their monthly average temperature on Saturday.

“Yes, you can say we are seeing a bit of an early start of the heatwave in several cities,” Chief Meteorologist Dr S. Sarfaraz told Dawn. “This happened because we couldn’t see rain-thunderstorms as expected in some areas under the westerly wave,” he explained.

With 48.5°C, Shaheed Benazirabad was the hottest place in province

He pointed out that the criterion of a heatwave was revised after the 2015 deadly heatwave. “Under this, the temperature should be four to five degrees above the monthly average and persist for at least five days,” he said.

Recalling the heatwaves in recent years, he said the 2015 heatwave in Karachi occurred due to the formation of an extraordinary depression and its intensity was restricted to the coastal city.

“In 2022, we saw a prolonged heatwave starting from March 15 and lasting till May 15 in Sindh and parts of Punjab,” he said.

Spike of 4.4°C in Karachi’s average May temperature

The Met department said that the maximum temperature in Karachi was 40.2°C, which shows an increase of 4.4°C as the monthly average temperature in May was 35.8°C.

What, however, made the weather conditions worse in Karachi on Saturday was a significant drop in humidity, or the amount of moisture in the air, from 66 per cent in the morning to 25pc in the afternoon.

The Met office said that Karachi’s temperature soared above 40°C for the first time this summer on Saturday.

However, the city, like the rest of the province, is expected to experience a slight drop in temperature over the next two days (Sunday and Monday) before returning to the heatwave conditions.

About the slight drop in temperature expected on Sunday (today), Dr Sarfaraz said the high-pressure area building up in the atmosphere was not stable yet.

“It would show its intensity post-May 20 and cover 70 per cent of the country, along with western and northern parts of India,” he said, adding that the heatwave would last till May 27.

Mercury crosses 46°C in 12 Sindh cities

On Saturday, at least 12 cities reported 46°C and above temperature.

With 48.5°C temperature, Shaheed Benazirabad reported deviation of 3.9°C from its monthly average temperature of 44.6°C. Dadu and Jacobabad both reported 47.5°C, registering an increase of 2.5°C and 3.7°C from their monthly average temperature, respectively.

Sakrand and Padidan both reported 47°C, an increase of 3.7°C and 3.2°C, respectively.

Other cities where maximum temperature was 46°C or above are Sukkur (46.3°C), Khairpur (46.2°C), Chhor (46°C), Larkana, Rohri, Moenjodaro and Mithi (46°C).

The maximum temperature in Hyderabad and Tanjojam was 45°C, Mirpurkhas (44°C), Badin (42°C) and Thatta (41°C).

“Very hot weather is likely with maximum temperature 46-48°C in upper and central districts of the province. Thunderstorm/light rain is expected in Kumbar Shahdadkot, Jacobabad and Shikarpur districts on Sunday afternoon/evening,” the department’s advisory says.

Published in Dawn, May 19th, 2024