The slowest fire season in British Columbia in a decade has heated up after a blaze near Okanagan Lake forced about 550 people from their homes and campsites.

By Tuesday evening, emergency officials had lifted the evacuation order, allowing the residents and campers to return to the small lakefront community of Trader's Cove, about 15 kilometres northwest of Kelowna, and to the Bear Creek provincial campsite.

But the order came only after the fire had extended to 39 hectares and come within about 400 metres of a home.

"Based on the progress firefighters were able to make today and the favourable weather conditions, there's very little wind in the area, the incident commanders have now deemed it safe for those that were evacuated to return home," Jason Brolund, Kelowna's deputy fire chief, said Tuesday evening.

Brolund said an evacuation alert remains in place, and residents can be asked to leave at a moment's notice.

He said campers can return to pick up their belongings but the campsite will remain closed.

"This is certainly the largest wildfire event that we've experienced this summer," said Brolund. "We haven't had much of a fire season up until now."

At one point, he said, the fire was 400 metres from a local home.

The wildfire broke out Monday night in a hard-to-reach canyon on the west side of the lake.

By Tuesday morning, 106 homes in the small lakefront community of Trader's Cove, about 15 kilometres northwest of Kelowna, and the nearby Bear Creek provincial campsite had been evacuated.

More than 100 high school seniors, who had gathered for an outdoor grad party, were also forced out of the area.

Evacuees were moved to an emergency reception centre in a community hall in the Westbank town centre.

Helicopters started attacking the fire at dawn Tuesday, but thick smoke hindered their efforts.

The fire's perimeter had grown to 39 hectares by Tuesday afternoon.

No one was hurt and no homes were damaged, said fire information officer Noelle Kekula.

Kekula said the exact cause of the fire is still under investigation, but it didn't appear to be natural

"We are saying it's person-caused," said Kekula.

Kirsten Jones, a spokeswoman at the emergency operations centre, said 165 people had reported to the centre by Tuesday afternoon.

"That means they've checked in and they've received any services that they do need," she said. "It might be food, shelter, clothing, you never know."

"I'm not getting the sense of urgency or even panic," she added. "It's all going very well, considering."

Monday night's blaze erupted near the end of a fire season that provincial officials have called the slowest in a decade.

B.C.'s wildfire branch has said the province has experienced about 500 wildfires this year, compared to 1,500 by this time last year. The province has so far spent about half the money fighting wildfires as it had by this time in 2010.

In one blaze last year, a fire scorched 107 hectares in West Kelowna before firefighters brought it under control. That blaze forced thousands of residents to flee the Rose Valley subdivision, but no homes were destroyed.

Memories remain vivid of the August 2003 fire at Okanagan Mountain Provincial Park. That fire forced the evacuation of about 27,000 people and burned about 230 homes in south Kelowna.

Provincial fire officials are also warning people about the hazards of campfires.

Fire officials in the Kamloops area reported finding 48 abandoned campfires between Friday and Sunday night.