Here in lower southeastern michigan (43rd parallel), it has begun as well. Cooler nights, shorter days, cooler air temps, you can see the birds and animals are already starting to feed up and hoard. A week ago (when air temp was 90F) Lake St Clair, that is fed by Lake Huron, was at 76-80 degrees. One week later it is at 66-69 degrees and the air temp today is going to be 75. This is after the last week we dropped from a week of 90F to a week of 60's.
Time to look for the schooled up bait and head to the lake arms and tributaries. Though, there are still many bass out deep.
Great time of year.
Cheers!