The beach is open from 6 am to 11 pm, but swimming is only permitted during the beach season when lifeguards are on duty from 11 am to 7 pm, in designated swim areas. The beach season runs from the Friday before Memorial Day, through Labor Day.
Located in the South Chicago neighborhood, Rainbow Beach totals 60.98 acres and features a gymnasium, fitness center and multipurpose rooms, handball courts, and one of the oldest community gardens in Chicago.
A natural area located at the northeast end of the beach includes 9.18 acres of dune habitat.
In 2013, the Park District is partnering with the Illinois Institute of Technology and the University of Illinois at Chicago to install a prototype stormwater filter to clean the rainwater that washes off of the parking lot onto the beach. This project is funded by a Great Lakes Restoration Initiative grant from the US Environmental Protection Agency.
The Green Stormwater Filter is an inground permeable reactive filter system that reduces bacteriological, algal, and chemical contamination caused by stormwater runoff from Rainbow Beach parking lot. Major benefits of this project include: reducing the number of pollution sources impacting Rainbow Beach, reducing beach water contamination and consequent swim advisories, reducing algal blooms and concentrations of nitrogen and phosphorus at Rainbow Beach area, and serving as pilot project for urban stormwater management for other Great Lake beaches.
Distance swimming is available parallel to shore at boat line.
Named for the U.S. Army's 42nd Rainbow Division that fought gallantly in World War I, Rainbow Beach and Park began as two separate municipal beaches. The first was established in 1908 by the Special Parks Commission, a city agency that studied open space needs and created parks, playgrounds and beaches in densely populated areas of Chicago.
At the time, this small site at 79th Street and Lake Michigan was known as Rocky Ledge Beach. The name referred to the area's rocky terrain, and to the manmade limestone ledge that served as a shore promenade and prevented shoreline erosion.
By 1912, the heavily used beach had bathrooms and changing rooms. Illuminated by electric lights, the beach remained open until 9:30 p.m. for the benefit of working men and women.
In 1914, the city began efforts to expand the beach, and soon acquired land between 75th Street and Rocky Ledge Beach. The City Council officially named the new site Rainbow Beach in 1918. The smaller, adjacent Rocky Ledge Beach continued operating as a children's beach. The two beaches were consolidated in 1959, when the Chicago Park District began leasing the site from the city.
For many years the park lacked sufficient indoor recreational facilities, so in 1999 the Chicago Park District constructed a large field house. Designed by David Woodhouse Architects, the field house takes full advantage of Rainbow Beach and Park's breathtaking views of the lakefront and skyline.