The outbreak of wildfires raging across Ireland because of the lengthy dry spell is unprecedented, according to fire chiefs.
Although many have been brought under control, conditions remain dangerous for further fires before an expected break in the sunny weather later in the week.
The Army has drafted 45 troops and three helicopters into west Donegal to help fire crews battle flames spreading across Muckish Mountain, near Falcarragh.
Two of the helicopters are fitted with "Bambi" buckets which are dropping up to 1,200 litres of water at a time onto the gorse blaze.
Major fires in Dungloe, Ardara and Glenties have been contained but teams are still tackling several other smaller fires, including in Buncrana and Milford.
Donegal's chief fire officer Bobby McMenamin warned landowners and the public to remain alert in the coming days.
He said: "Conditions are still ideal for gorse fires. We have windy conditions, very dry conditions out on the land and I would ask people to be very careful until the rain comes."
Thousands of acres have been destroyed as fires scorched gorse, bog and forests in Donegal, Leitrim, Laois, Offaly, Clare, Galway, Mayo, Roscommon, Monaghan, Cavan, Longford, Westmeath, Meath, Sligo and Louth. Several fires are still being tackled at Born na Mona lands between Ferbane and Edenderry, Co Offaly.
Meanwhile, Met Eireann said April was the warmest on record at most stations with temperatures around three degrees higher than normal.
Despite a wet start to the month, rainfall was also below average in most places with just 40% to 90% of normal showers recorded. However, totals were above average at Belmullet, Malin Head and Claremorris.