Both Canada and the US suffered a severe fire season. In Canada, the 2003 fire season was especially harsh in the Province of British Columbia. For example, in August 2003, the provincial government issued its most restrictive travel advisory ever after a wildfire near the city of Kelowna grew fivefold in a day. The wildfire at Okanagan Mountain Provincial Park, which started at a relatively manageable size, grew over several weeks, eventually covering more than 250 km² . Gusting winds, bone-dry forests and a lack of rain were blamed for the fire’s growth. Two-kilometre-wide fire fronts burned through timber at rates of up to 50 metres per minute. The Province of British Columbia estimates that it spent more than US$400 million fighting forest fires in 2003 (Makarenko 2003).
In the US, in October 2003, fires raging from just north of Los Angeles to the Mexican border became one of the worst natural disasters to strike California State in years, darkening the skies, and raining ash over much of the surrounding area (Figure 1). In all, the southern California fires killed 20 people, burned almost 300 000 ha and destroyed about 3 400 homes. They are considered the worst in the state’s modern history (Keating and Whitcomb 2003).