Mandera will experience downpours and probably "disastrous" flash flooding during the short rains from this month to December.
Otin Dipo, the meteorological officer in charge, said that flash floods previously have swept away crops along River Daua, the only permanent source of water for irrigation.
He urged residents living along the river banks and flood-prone areas to take precautions and move to higher ground.
The officer urged residents to store rain and floodwater that can be used during the dry season.
Takaba resident Mohamed Hussein said that they were happy the skies have finally opened.
"We thank God for the rains and we hope they continue for a few more months.We now have water and pasture for our animals after a long period of painful drought," he said.
Meanwhile, the National Drought Management Authority (NDMA) coordinator Hussein Alio deplored the heavy rains in the first week of October that killed many weak livestock.
Flash floods already have severed transport and swept away pasture and crops along the river.
More than 80 per cent of the county has received sustainable rainfall but killed more than 1,000 goats in Gither ward alone.
The region is characterised by long dry spells with animals suffering due to lack of pasture. The government has been supplying nutritious fodder pellets to sustain the livestock.
(Edited by V. Graham)