That far north if it's a sativa it may not even finish before it starts snowing, I've been to oshkosh is early fall, and it was damn cold! What are you working with? Maybe post a few pics? I'm in southern Colorado and only about half my crop is starting to flower right now, the rest have pistils present, but no active flowering yet. 9fingerleafs is exactly right, outdoors is pretty much a guessing game, I've got two plants for example, both cut from the same mother plant, one is in early flower, and the other one isn't even trying to flower yet right next to each other, I've harvested as early as the middle of September, and as late as the first week of November. All depends on weather, strain, sunlight accessibility, and a very important one, lack of artificial light from any source, a cell phone light can affect a plants flower cycle in a negative way. I faught the artificial light problem last night with my temporary neighbor at the air b&b leaving their back porch light on all night.