Mr Leary, a National Parks and Wildlife Service fire, incident and aviation training coordinator is back home to Queanbeyan earlier than expected, declaring his part of the job done and "one of the highlights of my career".

"The biggest differences to Australia are the terrain you're working in and the vegetation," he said.

"It's much steeper than Australia mostly, 50- to 80-degree slopes.

"It's too steep for vehicles - I didn't see a fire truck or bulldozer in a month.

"They fly aircraft to subdue the fire with people on foot on the ground to extinguish using hose lines and pumps."

Mr Leary was incident controller for the Cougar fire near the town of Boston Bar in southern British Columbia.

"Typically the head of a fire runs uphill and self-extinguishes, so we focused on the flanks.

"We had about 18 kilometres of hoses on a fire circumference of 30km and it started 300 metres above sea level and got to 1800 metres."

Mr Leary was part of a 102-strong deployment to Canada of Australian wildfire experts, alongside firefighters from Canada, Mexico, New Zealand, South Africa and the United States.

In an unprecedented season, more than 3.9 million hectares were burnt across Canada by more than 6000 fires, predominantly in British Columbia, more than double what occurred in 2014.

However, some relieving rain in adjacent Alberta province enabled consolidation of several large fires and reallocation of local staff and resources and gave an early mark from a planned 38-day deployment to the NSW NPWS contingent of 12, including Mr Leary.

British Columbia and Australia have shared and exchanged personnel, knowledge, skills, equipment and technology during emergencies for more than 15 years.

"It was a fantastic opportunity and experience to learn and pass on knowledge," Mr Leary said.

"Another thing that stood out was their safety conscious around burnt trees - after the initial process, they assess the line and mark hazardous trees to warn tree fellers and others before they allow them back to the fire line."