The India Meteorological Department (IMD) on Friday issued orange alert for six districts of Kerala on August 28 and 29 and forecast extremely heavy rainfall.

The weatherman has also issued a Yellow alert to all other districts in the state tomorrow. Orange alert was issued for the districts of Idukki, Palakkad, Malappuram, Kozhikode, Wayanad and Kannur on August 28 by the IMD, which predicted "extremely heavy rainfall" of around 20 cm. Also, the IMD issued Orange alert for the districts of Pathanamthitta, Kottayam, Idukki, Palakkad, Malappuram and Wayanad on Sunday while other districts in the state have been warned with a Yellow alert.

"The southwest monsoon has been vigorous over Kerala," the IMD website read and said rain occurred at most places in Kerala and Lakshadweep. The weatherman recorded 13 cm rain at Kozha in Kottayam district, 12 cm rain at Cherthala in Alappuzha district, 11 cm each at Aluva and Keerampara ARG, both in Ernakulam district. The IMD has also warned the fishermen against venturing into the sea till August 30.

"Strong wind with speed reaching 40-50 Kmph gusting to 60 Kmph is likely over Southwest and West Central Arabian Sea. Fishermen are advised NOT TO venture into these sea areas during the period mentioned," the MeT said.

A Red alert indicates heavy to extremely heavy rains of over 20 cm in 24 hours, while Orange alert means very heavy rains from 6 cm to 20 cm of rains. A yellow alert means heavy rainfall between 6 to 11 cm.