Milwaukee might see some lake effect also.I just asked the same question to my gardening friend. He says peas will bolt if planted at this time, not making good peas and pods but going straight to seed. For fall harvest, plant mid to late August.
I dont know if he is right or not, he is in Milwaukee area so different zone than me. I am planting peas on Friday and using a shade cloth. Peas produce in 60 to 70 days, that would be end of October if I planted end of Aug. it will frost by then. Wish me luck.
I think going to try planting some snap peas about Aug 10th see what happens. We are not short on seeds. Peas can take light frost, could cover or try to cover if hard frost.