Sarehe MP Maina Kamanda has asked the Nairobi government to adequately prepare for the El Nino.
Weather agencies worldwide have said the strongest and wettest El Nino will soon pummel East Africa.
Kamanda said drainages should be unclogged as many lives were lost, especially in slums, during torrential rains two months ago.
Speaking at the South B DO's office on Monday, Kamanda said more than 10 people died in Nairobi slums.
"We should not be caught off guard this time. We have time to prepare. Let us take the warnings seriously," he told the Star on the phone.
He said many motorists in Nairobi spent nights on the road.
The MP advised residents living along river banks to relocate.
Scientists said on Monday the El Nino will result in heavy rains, waterborne diseases and floods in East Africa.
In response to the El Nino warning, weather experts from East Africa will meet in Dar es Salaam to discuss how to handle the situation.
The Kenya Meteorological Department has asked Kenyans to be patient and wait for the report from the Dar es Salaam meeting.
Many people in Kenya were left homeless in the May torrential rains.
Many roads were impassable and some stuck in flood water, while houses were damaged by the flooding.
Residents said the flooding is mainly caused by poor drainage systems and waterways.