Hours and Admission Hours of operation:10 a.m. to 6 p.m. Fort Delaware is open the last weekend in April through the last weekend in September on a limited schedule. The fort is open weekends and holidays the last weekend in April through the last weekend in September. The fort is also open Wed, Thurs and Fridays mid June through Labor Day. Please contact the Fort Delaware park office for more information. Admission to seasonal programs is $6 for adults and $4 for children 2 to 12. Food concessions are open at Fort Delaware throughout the season. For more information, call (302) 834-7941