"Heat wave conditions very likely to prevail at isolated places over Kerala on May 1 and 2, especially in Palakkad and Kozhikode districts. People are advised to be careful while venturing out between 11 a.m. and 3 p.m.," said IMD on Sunday.
Palakkad recorded 41.6 degrees Celsius, Kozhikode 39.2, Kannur 37.8 and Punalur in Kollam district 37.6 degrees on Sunday.
Temperatures have surged in the past one week across the state.
According to the state disaster management authority officials, the present heat wave is the worst in the last five years.
Two deaths were reported on Saturday in Kozhikode due to the heat wave.
It is not so hot everywhere in Kerala though.
Kottayam and Thiruvananthapuram, for instance, received showers on Saturday.
Rainfall can be expected in more places in the state in the next four days, IMD said.