Why has it been so cold in Wisconsin lately?

I live in Milwaukee, and it has been way below what i remember it ever being in the summer. june is one of our hottest months of the year from what i remember. lately it's been in the mid 60's to mid 70's. if we're lucky it'll briefly get up in the 80's for one day then drop 20 degrees the next day. why is this? i dont remember it ever being this chilly. i gotta wear a hoody most of the time i go for a bike ride, cause even when it's sunny it's still only like 65 degrees cause it's so breezy.