About 950 firefighters backed by over 250 vehicles were battling the flames in areas of woodland mostly in the centre and north of the country, which is facing its worst drought in over six decades.
At the height of the series of wildfires earlier this week, more than 3,000 firefighters were at the scene of blazes, which claimed the life of a man in his 60s in central Portugal.
Firefighters said they had finally brought a wildfire which had burned since Monday in an area of thick woods near the central mountain town of Seia under control on Saturday morning but were monitoring it to guard against flare-ups.
The wind-fueled blaze destroyed more than 3,000 hectares (7,400 acres) of brush and woodland, making it the largest fire to hit Portugal this year.
Emergency services evacuated residents of 10 remote villages on Thursday because of the threat from approaching flames.
Portugal's Forest Fire Prevention Agency placed six of the nation's 18 administrative districts on maximum alert for wildfires on Saturday, five fewer than a day earlier due to the drop in temperatures in some regions.
Firefighters said strong winds which frequently changed direction, combined with scorching temperatures and drought conditions, had made it difficult to put out the flames.
Six firefighters have been killed so far this year in Portugal battling wildfires which have destroyed over 38,000 hectares of brush and forest.