Amid the coronavirus lockdown, the southern port city will witness a heatwave from May 5 to 8, the Meteorological Department said on Friday.
Met department Director Sardar Sarfaraz said that during the time period, mercury can rise up to 42 degrees Celsius in Karachi.
Sarfaraz said that during the heatwave, the sea breeze will remain suspended.
Due to hot winds blowing from the northwest, the weather will feel hot and humid, he said.
Karachi went through a two-day heatwave in the mid of April, where the temperature shot up to 40 degrees Celsius.
This time, the residents of the city will brace the harsh temperature while fasting during the holy month of Ramadan.
The city is also under lockdown orders as Sindh has recorded more than 6,000 coronavirus cases with 112 deaths.
