The fire issue is unpredictable but the risk of fires goes up as the season progresses. Weather is another issue as usually it is better in late August/early September than in late June/early July.
Early July feature Canada day weekend with crowds while early September features Labour day weekend with crowds so a draw there.
In late August/early September kids go back to school while in late June they get out of school so fewer families on the road in the fall.
Our personal preference in the Parks is early fall due to smaller crowds, nice temperatures, less chance of rain. Having said that we just got home from snow and cold temperatures in LaKe Louise and the south end of the B-J parkway but that was mid-September.
Tough call to make.
