There are a lot of cyclocross races scheduled in Ontario, Canada for fall 2013.
USA riders must purchase a UCI license from USAcycling.org for $150 to participate. Unfortunately, Canada no longer provides 1-day license purchases to riders without a UCI license. Unlike the USA, Canada does not have a national cycling organization. Instead, Canadian riders purchase a UCI license and then join a provincial racing organization. For Ontario, the provincial organization is Ontario Cycling (oca.org.)