Over 3,000 animals and exhibitions make this one of the country’s great zoological parks. Seasonal changeover dates are March 15 and October 1 New Hours: In Effect Jan. 2016 Current Hours Exhibit Buildings 9 a.m. to 4 p.m. (6 p.m. closing in summer) 10 a.m. to 4:30 p.m. (6 p.m. closing in summer) Grounds 8 a.m. to 5 p.m. (7 p.m. closing in summer) 6 a.m. to 6 p.m. (8 p.m. closing in summer)