"They are hit by shortages of drinking water and damage to crop," Pradeep Kodippily, spokesman for the disaster management centre, said.
Most irrigation tanks in the island have run dry, the Irrigation Department said.
According to the Water authorities, restrictions have to be placed on the drinking water supplies.
The hydro powered electricity capability has also been affected.
The governmenthas requested that all air conditioners be set at 26 degrees in view of the electricity supply being affected by the drought.
Lankan President Maithripala Sirisena's office said that UN agencies - Food and Agriculture Organisation (FAO) and World Food Programme (WFP) - called on him yesterday to assure international assistance to extend drought relief.
Sirisena on Friday appointed a special task force with the participation of all related institutions to make preparations to face the severe drought prevailing in the country.