🌤 Weather at Fort Delaware State Park by season
| Spring | Summer | Fall | Winter |
|---|---|---|---|
| 34–74 °F | 63–87 °F | 37–78 °F | 26–46 °F |
Each range runs from the coldest monthly average low to the warmest monthly average high in that season (1991-2020 climate normals), measured at Wilmington New Castle Co Airport, 7 mi away, elevation 79 ft. Conditions at the park can differ from the station, especially where elevation differs — check a forecast before you go.
🏆 Island Fortress — Civil War-era island fortress in the Delaware River — Fort Delaware held up to 12,500 Confederate prisoners of war, making it one of the largest POW camps in the North! The granite and brick pentagonal fort on Pea Patch Island is accessible only by ferry. Legend says the island formed when a boat carrying peas sank, and the peas sprouted to create the island!
Visitor Information
| Detail | Info |
|---|---|
| Location | Pea Patch Island, Delaware City |
| Access | Ferry only! |
| POWs | 12,500 Confederate prisoners! |
Getting There
Accessible only by ferry from Delaware City (March-November). The boat ride across the Delaware River is part of the experience. Fort Delaware sits on Pea Patch Island — named, legend says, because a colonial ship carrying peas ran aground and the peas grew on the island. Combination tickets with Fort DuPont are available. Ghost tours are offered in October — with 2,700+ deaths, spirits supposedly abound.
Plan Your Visit
Fort Delaware is accessible only by ferry from Delaware City (March-November, $12 adults). The massive granite-and-brick fort is one of the best-preserved Civil War fortifications on the East Coast. Living history programs feature uniformed interpreters portraying guards and prisoners. Ghost tours are offered in October. Combine with Fort DuPont State Park (adjacent in Delaware City) for a full Civil War heritage day. Pea Patch Island also hosts a great blue heron rookery.
Nature & Wildlife
Pea Patch Island hosts one of the largest wading bird rookeries on the East Coast — great blue herons, cattle egrets, black-crowned night herons, and glossy ibis nest in the island’s woodland canopy. Over 10,000 pairs of herons breed here annually. The rookery is protected and not accessible to visitors, but birds are easily observed from the fort’s ramparts. Horseshoe crabs spawn on the island’s beaches each May.
Insider Tips
Civil War prison: Fort Delaware on Pea Patch Island held up to 12,500 Confederate prisoners — conditions were so harsh it was called the “Andersonville of the North.” Pro tip: An estimated 2,460 prisoners died here. Island fortress: The massive granite fort was built 1848-1868 to defend the Delaware River approaches to Philadelphia and Wilmington.
Frequently Asked Questions
How bad were Civil War prisons?
Civil War prisons on both sides were horrific — Andersonville (Confederate) and Fort Delaware (Union) had mortality rates of 20-30%. Overcrowding, disease, starvation, and exposure killed thousands. Approximately 56,000 soldiers died in captivity during the war — roughly 10% of all deaths. The breakdown of prisoner exchanges in 1863 (over the treatment of Black soldiers) worsened conditions dramatically. Both sides used prison conditions as propaganda.
More parks nearby: Fort DuPont State Park is a short drive away, while Lums Pond State Park lies a short drive away.
🐾 Dogs & Pets at Fort Delaware State Park
- Pets allowed? statewide rule
- Delaware State Parks are pet-friendly: leashed pets are welcome in most park areas, but all pets must be licensed with proof of rabies vaccination, and picnic areas, park buildings and yurts are closed to pets.
- Leash rule statewide rule
- Leash no longer than 6 feet, except in designated off-leash areas.
- Beaches & swim areas statewide rule
- State law prohibits pets from all swimming and sunbathing beaches May 1 - September 30; Beach Plum Island bans pets year-round.
- Cabins & lodging statewide rule
- Only dogs are allowed, and only in designated dog-friendly units (e.g. cabins at Killens Pond, Trap Pond, Cape Henlopen, cottages at Delaware Seashore); $25 per night pet fee, 2-dog maximum.
- Pet fees statewide rule
- No day-use pet fee; $25 per night pet fee for dog-friendly cabins/cottages (max 2 dogs).
- Statewide exceptions statewide rule
- Fort Delaware State Park and Killens Pond Water Park are closed to pets; pets allowed in surf-fishing vehicle areas on a 6-foot leash.
Are dogs allowed at Fort Delaware State Park?
Delaware State Parks are pet-friendly: leashed pets are welcome in most park areas, but all pets must be licensed with proof of rabies vaccination, and picnic areas, park buildings and yurts are closed to pets. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via destateparks.com. More: Delaware state parks guide · Dog rules in all 50 states compared
Park Location
Plan your gear for Fort Delaware State Park
From our editorial guides, matched to this park’s activities:
Top Tours & Activities Near Amboseli National Park
from $725
from $5,670
from $6,642