An operation to bring a number of gorse fires in Co Donegal has been called off for the night.
Fires on Coillte lands in Mayo and in Connemara have been extinguished but a small number of personnel will remain on standby overnight to monitor the situation.
Elsewhere, a fire was reported on a hillside in the Dromahair area of Co Leitrim.
The fires have been spreading quicker than would normally be the case because the severe frosts during the winter damaged vegetation.
In Northern Ireland, firefighters have been tackling a string of wild fires on the Mourne Mountains.
The fire service said it believes some had been started deliberately and described the fires as the most serious in years.
Earlier, the Defence Forces were deployed to help in the operation.
Fires were reported in counties Donegal, Galway, Mayo, Longford, Westmeath, Offaly and Down.
Fifty troops were deployed in Donegal and north-west Mayo and an Air Corps helicopter, equipped with a bucket, flew missions to drop 1,200 litres of water at a time on the fires near Dunloe.
A second helicopter conducted a similar operation at the Foxford Pontoon area of Mayo.
Twelve units of the fire service tackled a large gorse fire between Lettermacaward and Dungloe in west Donegal.
Four houses in the area were evacuated, and one house was said to be extensively damaged.
The Donegal Fire Service has said the blaze was started maliciously.
A strong breeze and dry conditions has hampered efforts to bring the fires under control.
Firefighters and forestry workers battled a number of serious bog and forest fires in Galway and Mayo.
One of the most serious of the fires has damaged four square kilometres of bog and forestry between Pontoon and Castlebar.
Another large fire broke out near Recess in Connemara and is causing extensive damage in the Lough Inagh Valley area.
Five units of the fire brigade tackled a bog and forest fire on the Longford/Westmeath border.
The blaze broke out near the village of Lismaccrey. There were a number of smaller fires reported in counties Offaly, Westmeath and Longford over the weekend, but this is the largest reported incident.
The PSNI has warned the public against walking in the Mourne Mountains in Co Down over the next few days because of the danger from gorse fires.