Most places in western canada are pretty good in august. There are a few sport areas around squamish, in particular cheakamus canyon.
Lake Lousie has some sport, but camping options seemed to be very non convenient and expensive.
We found some very hard limestone sport climbing on vancover island at horne lake.
In the states in august your options are pretty much alpine areas or chasing the shade. Rifle canyon in colorado has heaps of sport climbing on both sides of a narrow canyon. So you can climb on one side in the morning and the other in the arvo. Castle rock state park in idaho has quite a bit of sport climbing and you can avoid the sun most of the day.