Cannabis will not switch to flower until she's only getting 12 to 13 hours of light, max. If you leave them outside, you'll have to wait till seasons change, or find a way to block the last few hours of sunlight every day.

Be careful bringing plants inside from outside, (bugs and insects) and make sure you have appropriate lighting for them.
If you do bring them in, likely that's where they'll have to stay till harvest.