It depends on a few factors, but I'm around the same latitude (maybe a little higher) then you are and my plants have not begun to flower. If you have some that were trying to flower since June 1st it might of been that you just put them outside and they were getting 18-24 hours of light indoors, am I correct?? Its not called half vegging half blooming :D Its called reveg, its when they get outside and they start to flower because of the reduction in light, then they realize that its not time to flower so they start to veg again, hence reveg. Anyways, in North America the average day is around August 1st, sometimes sooner depending on other factors. So if they are starting to flower now, thats fine.