This paper aims to understand the magnitude of cross-provincial spillovers from wildfire smoke, and the implications of these spillovers on how wildfire management is structured in Canada. Canada’s wildfire management regime is decentralized—with provinces responsible for the majority of wildfire management duties. However, economic theories on decentralization show that, in the presence of inter-jurisdictional spillovers, such a system may not be optimal. If spillover effects are unilateral—one province affects another more than vice versa—then there is reason to have greater centralization. Although there are inefficiencies related to centralization, polycentric theories show that such inefficiencies may be necessary when it comes to emergency management due to the need for resource redundancy. My research uses Distributed Lag Models to determine the impact of wildfire burn area on smoke levels across 22 Canadian municipalities. The results show that, during the wildfire season, approximately 75% of PM 2.5 levels in Canadian municipalities is attributable to cross-border wildfires. Therefore, the impacts of cross-provincial spillovers are not only large, they are greater than intra-provincial wildfires on municipal smoke levels. These results show that wildfire smoke is a matter of national concern, which implicates greater federal responsibility in wildfire management.