From the South Milwaukee Police Department …
Cost of the permits is $30.00 per month or $100.00 for the entire 4 month season. Any resident who wishes to park on the street between the hours of 3am and 6am must purchase a parking permit.
Alternate side parking rules also apply. Winter parking is enforced 7 days a week.
PLAN AHEAD, get your permits early. Parking permission will not be given because you did not have time to purchase a permit.
More details here.