The Cook Islands meteorological service says a continuing dry spell has left some homes without a water supply.
The Director of Meteorological Services, Arona Ngari, says the current dryness is consistent with El Nino, with rainfall in the southern group far below average.
Latest statistics show that only 35 millimeters of rain fell in October, compared to 102 mm for the same period last year.
The PacNews news agency reports over 40-thousand litres of emergency supplies of water have been delivered to homes in Nikao, Ruatonga and Avatiu.
Mr Ngari says the dry spell is due to movement of the South Pacific Convergence Zone, or SPCZ, away from its normal position.
"In an El Nino period or episode the El Nino pushes this SPCZ towards the east of it's normal position. That would indicate then that the bottom part of the SPCZ will probably lie over the off-shore groupings of French Polynesia, while the northern part of the SPCZ will hang over the northern Cooks. So they will get a lot of rain, while for the southern Cooks we will be bombarded by dry south easterlies, which means less rainfall."
Mr Ngari says normal rainfall may not come back to the country for another six months.