The Terrace Mountain blaze, near West Kelowna, is believed to be about 90 per cent contained.
But the Regional District of Central Okanagan says there was increased activity and behaviour at the fire site Saturday afternoon, sparking the evacuation order.
Evacuated residents have been told to report to an emergency social services centre in West Kelowna.
The Fintry residents are being evacuated as more than 2,000 people in the B.C. town of Lillooet remain on evacuation alert.
The Mount McLean fire, near Lillooet, is estimated at 26 square kilometres and is just one kilometre away from the community.
Meanwhile crews are having only limited success in dousing a dangerous forest fire which has left 2,300 residents of Lillooet, B.C. on evacuation alert and prepared to abandon their homes at a moments notice.
It means firefighters in the area are thinking of doing a controlled burn using fire guards which were left behind after the huge forest fires in 2003.
"If water can't do anything, we will try to remove the fuel between the fire and the guards if conditions permit,'' said Isabelle Jacques, a spokeswoman for the B.C. Forest Service.
See Related links: Fire threat leaves Lillooet on full alert
According to the B.C. Forest Service website, the Mount McLean wildfire is burning about four kilometers west of Lillooet. But a CTV News reporter said the fire may actually be much closer to the B.C. town.
The fire to the west of the district, on the east side of Mount McLean, has grown from 22 hectares to approximately 75 hectares, pushing it about a mile and a half (less than three kilometers) from the municipal boundaries," said Jerry Sucharyna, a public information officer for the District of Lillooet.
He was speaking to CTV News Channel in a phone interview from Lillooet on Saturday.
The fire has not grown in size since Friday evening, but it has also not been contained, Sucharyna said.
Residents know that they may have to leave their homes at any moment.
"We've informed the public to be ready to go on a short notice and with that, to pack whatever they are going to require...That's why the alert was put out ahead of time, so that people could prepare for that." he said.
Thunderstorms have been forecasted for Saturday afternoon and high winds and lightning strikes could hamper the efforts of firefighters, who are working in temperatures which reached 37 degrees Celsius on Saturday.
Meanwhile, the B.C. Forest Service says a fire on Blackcomb Mountain in Whistler is now 50 per cent contained.
That fire, on the mountain that will host bobsleigh, luge and skeleton events during the 2010 Olympics, is estimated at about 30 hectares.
With a report by CTV British Columbia's Kent Molgat, and files from The Canadian Press
