The red weather warnings have been extended to Waterford, Wexford and Limerick
Hurricane Ophelia is expected to be the worst storm to hit Ireland in over 50 years.
The National Co-Ordination Emergency Group has extended the red weather warnings and is advising people to stay inside in areas expected to be worst-hit.
A red warning will be in place for Limerick, Waterford and Wexford, in addition to Galway, Clare, Cork, Kerry and Mayo.
An orange level warning is in place for the rest of the country, with the storm expected to bring winds in excess of 130 km per hour as well as coastal flooding.
The Department of Education says all schools in the 8 counties under a red status warning will be closed tomorrow.
Home, land and business owners are being urged to be aware of flood risk, high seas and stormy conditions as the storm approaches.
Bus Eireann has cancelled school buses on Monday in for areas in which a red warning is in place, while the RSA is warning road users to take extra care.
The ESB is also advising customers to be careful, due to the possibility of falling wires and electricity outages.
Taoiseach Leo Varadkar says the Defence Forces will be deployed in areas where a status red warning is in place.
Defence forces being deployed in Red weather alert areas and on standby for further action tomorrow— Leo Varadkar (@campaignforleo) October 15, 2017