Every year worldwide some extraordinary wildfires occur, overwhelming suppression capabilities, causing substantial damages, and often resulting in fatalities. Given their increasing frequency, there is a debate about how to address these wildfires with significant social impacts, but there is no agreement upon terminology to describe them. The concept of extreme wildfire event (EWE) has emerged to bring some coherence on this kind of events. It is increasingly used, often as a synonym of other terms related to wildfires of high intensity and size, but its definition remains elusive. The goal of this paper is to go beyond drawing on distinct disciplinary perspectives to develop a holistic view of EWE as a social-ecological phenomenon. Based on literature review and using a transdisciplinary approach, this paper proposes a definition of EWE as a process and an outcome. Considering the lack of a consistent “scale of gravity” to leverage extreme wildfire events such as in natural hazards (e.g., tornados, hurricanes and earthquakes) we present a proposal of wildfire classification with seven categories based on measurable fire spread and behavior parameters and suppression difficulty. The categories 5 to 7 are labeled as EWE.

Previous experience with a hazard has been identified as influencing risk perception and adoption of adjustments. However, this relationship is not clear and may depend on the differences in experiences that may occur within a community. This article describes residents' wildfire experiences and explores how these experiences may influence risk perceptions and implementation of mitigation measures 1 year after the 2003 Lost Creek and McLure wildfires in western Canada. Interviews were conducted with 40 residents with different wildfire experiences, including losing their home, being evacuated, self-evacuating early, staying in their house during a wildfire, and being away from the area. Results suggest that differences in hazard experiences can impact post-event risk perceptions and adoption of mitigation measures. Management implications are discussed.

Each year wildfire affects communities in Canada, resulting in evacuations and, in some cases, loss of homes. Several Canadian wildfire management agencies have initiated mitigation programs aimed at reducing wildfire risk. Successful wildfire mitigation involves both community-level and homeowner action. This paper examines factors that influence wildfire mitigation by homeowners. We draw upon the general hazards and wildfire management literature to develop and test a theoretical model for homeowner wildfire mitigation that includes perceived risk, an evaluation of threat significance and the influence of perceived costs and benefits of mitigation. We used a mail survey to collect data from 1265 residents in six interface communities in the province of Alberta. Results showed a high level of completion for most mitigation activities. A structural equation model provided support for the hypothesis that the evaluation of threat involves weighing the negative effects of mitigation on homeowners’ feelings of connectedness to nature and the cost of mitigation with the positive influences of fear, a sense of responsibility and perceived effectiveness of mitigation. Considering the total effects, threat assessment had the greatest effect on mitigation by homeowners, followed by perceived effectiveness of mitigation in reducing damage and not having financial resources for mitigation.