The weatherman says Kenyans should brace themselves for heavy rainfall of more than 50mm in 24 hours starting Thursday.
The downpour, according to the forecast released on Tuesday, will be experienced in western Kenya, Rift Valley, Nyanza and central Kenya.
A dispatch from the Kenya Meteorological Department said the heavy rainfall would be recorded in Kisii, Kericho, Bomet, Narok and Migori counties.
Others are Kakamega, Kajiado, Nakuru, Kwale Marsabit, Turkana, Samburu, Nairobi, Nyeri, Kiambu, Muranga, Kitui, Machakos, Makueni and Taita Taveta.
Kenyans living in towns have been advised to be on the lookout for flash floods, which killed more than five people last year.
Dry river beds may also be filled with moving water while soil erosion may ravage areas with dry and bare soils.
"However this is not the proper onset of the March-May rainfall season," the report reads in part.
The dispatch indicates that the heavy rainfall is likely to continue on Friday, March 2, over counties in the South Coast, western Kenya, Nyanza, Rift Valley, northern Kenya, and central Kenya, including Nairobi and southeastern lowlands.
On Saturday, March 3, the weatherman said counties in western Kenya, Nyanza, Rift Valley, central Kenya and south-eastern lowlands would continue receiving heavy rainfall in the afternoon.
The rains are expected reduce in intensity over the eastern, Coast and northern regions but moderate rainfall will continue over the rest of the country.
The weatherman advised Kenyans to look out for updates if conditions change significantly.
The alert comes as more than 241,000 Coast residents face starvation, with children bearing the brunt.
Kilifi, Tana River and Taita Taveta counties have been hardest hit by drought, according to Kenya Red Cross Society.
Some Kilifi residents have turned to charcoal burning to make ends meet, depleting forest cover in Adu and Galana ranches.
"In Taita Taveta approximately 77,000 people are facing starvation, Tana River 35,000 and Kilifi 129,000," said Kenya Red Cross Society regional manager Hassan Musa.
"Kilifi is worst hit, especially in Magarini, where 51,000 people suffering due to lack of food and water. In Bamba-Ganze 41,000, Kaloleni 20,000 and Malindi 10,000 people are starving."