Heavy rainfall is likely in one or two places in the State on Tuesday, the India Meteorological Department (IMD) said.
The weather agency has put Ernakulam, Idukki, Thrissur, Malappuram, Kozhikode, Kannur and Kasaragod on yellow alert on Tuesday.
A low pressure area that has formed over the Bay of Bengal off the south Odisha and north Andhra Pradesh coasts is likely to move west-north-westwards over the next four to five days.
Fishermen have been warned that squally weather is likely along the Kerala, Karnataka coasts and the Lakshadweep region till Tuesday.
The monsoon rainfall deficit this season in the State stands at 20%, as on Monday.