Pools generally open at different times depending on the location and type of pool:

• National Pool Opening Day is celebrated on the last Saturday in April each year, encouraging pool owners to prepare their pools for summer. For example, in 2025, this day falls on April 26

• In Washington, DC, outdoor public pools open on weekends only before June 22, 2025, including Memorial Day (May 26, 2025). After June 22, pools operate six days a week on individual summer schedules

• In New York City, outdoor pools typically open daily with hours from 11:00 a.m. to 7:00 p.m., but exact opening dates are not specified in the search results

• Some community pools, like those in Cape Town, operate seasonally with phased openings. For example, pools may be open daily from early December to January, then weekends only until March, and daily again from late March to April

• In Dallas, community pools have opened in early June in recent years, such as June 4, 2022

• In some areas, people open their private pools about two weekends before Memorial Day, which is late May, to have a clear pool ready for summer

• Chicago outdoor pools typically open in mid-June and close before the school year starts in August

In summary, while private pools often open around late April to early May (coinciding with National Pool Opening Day), public outdoor pools in many U.S. cities tend to open around late May to mid-June, with some variation by location and pool type.