Residents in Coosan, Assumption Road, Beechpark, and Clonbrusk will have their water turned off from 11pm tonight to 8am Sunday.
Irish Water is also asking housholders across Westmeath not to use dishwashers or washing machines and to take showers instead of baths.
It comes as Irish Water said high night time demand in Athlone recently has resulted in the water level in the Annagh Reservoir dropping.
As a result water will not be pumped to the Coosan area and the Batteries Water Tower tonight.
The water restrictions tonight will help to replenish the reservoir levels.
It may take up to 9.30am on Sunday for water to be restored to all customers in the Cossan area.
Customers on the Westside of Athlone town are not expected to experience water loss but may have reduced pressure.
Repairs will be carried out on leaks in the public network in Athlone on Church Street and Cornamagh tomorrow and on Monday as weather and ground conditions improve.
Reservoir levels in Castlepollard, Delvin and Clonmellon and in Mullingar are critically low due to high water demand and high turbidity in the raw water sources. Work is continuing to meet the water demand to supply homes and businesses and further updates will be provided throughout the day.
Customers throughout Westmeath are urged to conserve water by not running taps unnecessarily, taking showers instead of baths and to refrain from using dishwashers and washing machines.
Irish Water said it thanked customers for their patience while it worked to resolve all issues due to the extremely cold weather conditions and would like to apologise to customers for any inconvenience caused.
Updates will also be posted to the supply and service section of Irish Water’s website at www.water.ie/water-supply/supply-and-service-update/ .
Customers can contact our call centre 24/7 on 1850 278 278 or on Twitter @IWCare.