Bobmar if by that you mean to avoid the CFL, you couldn't. The CFL actually starts in mid-June with two pre-season games for each of the eight teams in the league. That is followed by a regular season that begins on the July 1 weekend and concludes with the Grey Cup championship the last weekend in November. At that point many football fans turn their attention to the NFL, who are now into the homestretch in their regular season, concluding with the Super Bowl the first weekend in February. And, for Canadians at least, the NHL season ends at around the same time football is beginning. I not sure there is a perfect time to play rugby league in Canada, other than to say pick a time and just go for it. Just as a qualifier, while summer begins in Canada on about June 21 and goes to about Sept. 21, it is more a state of mind. Many feel summer begins on the May Long Weekend holiday which is the third weekend in May, and ends on the Labor Day weekend which is the first weekend in September. If it were up to me out here on the West Coast, I would start a season in August and end around the end of October. Here in BC the days are hot in early August, but the nights are cool, while you can get great weather, that is, moderate temperatures and reasonably dry conditions well into October. Of course, this time frame would conflict with union who begin games in September and play until early December, then take a break until February before picking up again and playing until April-ish.
