Heavy rainfall would occur at isolated places in Kerala from May 6 till the morning of May 8, it said.
Heat wave conditions continued in parts of Kerala on Wednesday but some respite is expected with rains or thundershowers forecast in the next four days.
Palakkad, which has been bearing the brunt of the soaring temperature for the past more than a week, today recorded a maximum of 40.8 degree Celsius.
The Met office in Thiruvananthapuram said a few places in Kerala and Lakshadweep would receive rain and thundershower till May 8.
Heavy rainfall would occur at isolated places in Kerala from May 6 till the morning of May 8, it said.
Though heat wave conditions continued to prevail in many parts of the state, no sun stroke related incidents was reported on Wednesday, health department sources said.
As many as 296 persons had suffered sun burns across the state since March, they said.
Kozhikode recorded 38.3 degrees Celsius, Kannur 37.4 degrees Celsius, Punalur 38.3 degrees Celsius and Thiruvananthapuram 35.6 degrees Celsius, the MeT department said.
In view of the rising mercury levels, authorities in many districts have already ordered that educational institutions should remain shut until further directive.