New Castle is a city in New Castle County, Delaware, home to about 5,579 people across 3.5 square miles. It has no ZIP code of its own: it’s part of 19720.
Homes sold for a median of $203 per square foot in the three months ending August 2026, a seller’s market.
Part is in New Castle, part in Wilmington Manor and Bear
Each card is that ZIP code’s whole market, including any part outside New Castle. Seller’s market: under 4 months of supply; buyer’s market: over 6. Methodology
We’re writing up New Castle’s story and what everyday life there is like, for people thinking about moving in.
Are you a local agent who knows New Castle well? Agents who advertise here will be able to write the guide. Advertise on OfferBacked
| Nearest major airport | Philadelphia International Airport (PHL)29 miles away |
|---|---|
| Closer regional airport | Wilmington Airport (ILG)6 miles away |
| Nearest city of 250,000+ | Philadelphia, PA40 miles away |
Straight-line distances from the center of New Castle; driving is longer.
Source: Airports from OurAirports (scheduled passenger service); city centers and populations from the U.S. Census Bureau.
Source: Members of Congress from the congress-legislators project; districts from the Census Bureau’s relationship files; governor and mayor from Wikidata.
New Castle had 5,551 residents in the 2020 census, up 14% since 2000.
It’s the 21st largest of 79 towns in Delaware by population.
New Castle County grew from 109,697 residents in 1900 to 570,719 in 2020.
New Castle County, 1900–2020
Source: U.S. Census Bureau decennial censuses (counties 1900–1990 from the Bureau’s historical county file).
Average highs peak around 87°F in summer, and winter lows average 26°F. About 45.5 inches of rain and melted snow fall in a typical year, with about 20 inches of snow.
Source: NOAA 1991–2020 climate normals, Wilmington New Castle Co Ap, DE weather station (6 miles away).
306,745 jobs at 17,855 businesses in New Castle County. The biggest industries by employees:
Source: U.S. Census Bureau County Business Patterns 2023 (private employers; jobs counted where people work).
374 doctors and other health care providers list an office in New Castle.
Nearest hospitals
Providers with an office here
| Primary care doctors | 23 |
|---|---|
| Specialist doctors | 53 |
| Dentists | 9 |
| Nurse practitioners and physician assistants | 53 |
| Mental health providers | 151 |
| Physical and occupational therapists | 76 |
| Optometrists | 3 |
| Chiropractors | 6 |
| Pharmacies | 19 |
Source: Hospitals from CMS Hospital General Information (ratings are CMS overall star ratings); straight-line distances; providers from the CMS National Plan and Provider Enumeration System (NPPES), by practice address and primary specialty.
Parks (1 nearby)
Grocery stores
Pharmacies
Libraries
Theaters and performance venues
Counts are within about 1.5 miles of the center of town.
Source: Map data © OpenStreetMap contributors (openstreetmap.org/copyright), as mapped by volunteers; it can miss places or include closed ones.
Public schools here are run by Colonial School District, Charter School of New Castle. Check each district’s attendance zones for a specific address.
| School | Grades | Students | Type | Distance |
|---|---|---|---|---|
| Leach (John G.) SchoolNew Castle | Pre-K–12 | 95 | Special Education | 8.2 mi |
| The Colwyck CenterNew Castle | Pre-K | 222 | Public | 8.2 mi |
| Castle Hills Elementary SchoolNew Castle | K–5 | 462 | Public | 7.6 mi |
| Charter School of New CastleNew Castle | K–8 | 788 | Charter | 8.2 mi |
| Downie (Carrie) Elementary SchoolNew Castle | K–5 | 324 | Public | 6.4 mi |
| Eisenberg (Harry O.) Elementary SchoolNew Castle | K–5 | 436 | Public | 8.3 mi |
| New Castle Elementary SchoolNew Castle | K–5 | 383 | Public | 6.5 mi |
| Pleasantville Elementary SchoolNew Castle | K–5 | 389 | Public | 5.3 mi |
| Southern Elementary SchoolNew Castle | K–5 | 729 | Public | 2.4 mi |
| Wilmington Manor Elementary SchoolNew Castle | K–5 | 291 | Public | 7.3 mi |
| Bedford (Gunning) Middle SchoolNew Castle | 6–8 | 846 | Public | 2.3 mi |
| McCullough (Calvin R. ) Middle SchoolNew Castle | 6–8 | 615 | Public | 8.8 mi |
| Read (George) Middle SchoolNew Castle | 6–8 | 662 | Public | 6.8 mi |
| Penn (William) High SchoolNew Castle | 9–12 | 2,069 | Public | 6.3 mi |
| The Wallace Wallin SchoolNew Castle | Ungraded | — | Special Education | 6.4 mi |
| School | Grades | Students | Affiliation | Distance |
|---|---|---|---|---|
| Harvest Christian AcademyNew Castle | Pre-K–12 | 94 | Christian (no specific denomination) | 6.4 mi |
| Harvest Christian Academy New CastleNew Castle | Pre-K–12 | 100 | Christian (no specific denomination) | 6.4 mi |
Source: U.S. Department of Education, NCES: Common Core of Data (2024-2025) for public schools; Private School Universe Survey (2023-2024) for private schools. Listed by address; we don’t rate schools.
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Shares ZIP codes with Wilmington Manor, Bear and St. Georges.
Town boundaries don’t always match ZIP codes: a ZIP code can cross into neighboring towns, and a town can share a ZIP code with its neighbors. Facts describe the town itself; market figures describe whole ZIP codes.