The Department of Agriculture, Food and the Marine advised that extreme or high forest fire risk conditions exist at present.
These conditions are expected to continue over the weekend.
Poor growth so far this year means that ground vegetation can dry out quickly with just a short period of dry weather.
Fires could grow and spread much more rapidly than expected in these circumstances.
Donegal County Council has appealed to landowners and members of the public to take all necessary measures to prevent gorse, heather, forestry and similar fires.
The Fire Service responded to 179 wildfires since March 28 this year.
People are asked to report uncontrolled or unattended fires immediately by dialling 999 or 112