South Central Connecticut Planning Region area

Population and density of South Central Connecticut Planning Region

The Census Bureau estimates that 578,741 people lived in South Central Connecticut Planning Region on July 1, 2025. That ranks #125 of 3,222 county equivalents nationally and #3 of 9 in Connecticut. Since the April 1, 2020 estimates base of 570,746, the population has grown by 7,995 (+1.4%), compared with +2.2% for Connecticut as a whole.

With 367.3 square miles of land, that is 1,576 people per square mile (608 per km²), placing South Central Connecticut Planning Region #111 nationally for density and #2 in Connecticut. The median county equivalent has 47 people per square mile; the Connecticut median is 968. Put another way, there are about 0.406 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in South Central Connecticut Planning Region

South Central Connecticut Planning Region is divided into 15 cities and towns. In Connecticut, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is New Haven town, with 138,774 residents (24% of the county). The largest by land is Guilford town, at 47.1 mi², or 12.8% of the county’s land. Among those with at least 1,000 residents in 2020, New Haven town grew fastest since then (+3.6%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside South Central Connecticut Planning Region. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

South Central Connecticut Planning Region is a central county of the New Haven, CT Metropolitan Statistical Area. South Central Connecticut Planning Region is the area’s only county equivalent, so the metro area has the same 367.3 square miles of land. By combined land it ranks #382 of 393 metropolitan areas, and #101 by population. It belongs to the New Haven-Hartford-Waterbury, CT Combined Statistical Area.

ZIP codes

24 ZIP Code Tabulation Areas have land in South Central Connecticut Planning Region, and each lies mostly inside the county.

064050643706443064500645106460064610647106472064730647706492065100651106512065130651406515065160651706518065190652406525

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Post-office-box and single-address ZIP Codes have no tabulation area. Connecticut areas are assigned through their towns, because planning regions replaced the state’s counties after 2020.

Counties bordering South Central Connecticut Planning Region

South Central Connecticut Planning Region shares a land border with 4 county equivalents. It has more land than 1 of them. The largest neighbor is Capitol Planning Region (1,027.4 mi²) and the smallest is Greater Bridgeport Planning Region (140.2 mi²). Together with its neighbors, South Central Connecticut Planning Region forms a block of 2,371.7 mi² of land, of which it holds 15.5%.

How big is South Central Connecticut Planning Region compared with U.S. states?

South Central Connecticut Planning Region has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.8 times as much. Connecticut’s county land could hold about 13 areas the size of South Central Connecticut Planning Region.

Another way to picture it: the same land area would fill a square about 19.2 miles (30.8 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about South Central Connecticut Planning Region?

South Central Connecticut Planning Region has more land than 583 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places South Central Connecticut Planning Region at #1,678 nationally by total area, 961 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 40.7%, compared with a national county-equivalent median of 1.2% — 39.6 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside South Central Connecticut Planning Region in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.