Western Connecticut Planning Region, CT vs Suffolk County, NY

Neighbouring counties across the Connecticut and New York state line, compared on population, size, income and housing. They share 7.6 mi of border.

Both outlines are drawn at true relative size. Suffolk County spans about 128.9 km at its widest.

Side by side

Western Connecticut Planning Region, Connecticut and Suffolk County, New York on shared measures. The middle column is the difference, computed from the two figures either side of it.
MeasureWestern Connecticut Planning RegionDifferenceSuffolk County
Population640,482-58.6%1,546,090
Change since 20203.5%+1.9 pp1.6%
Land area532.1 sq mi-41.6%910.9 sq mi
Population density1,204 per sq mi-29.1%1,697 per sq mi
Median household income$128,188-1.9%$130,686
Median home value$652,900+12.9%$578,400
Median age41.5-0.5%41.7
Households235,379-54.1%512,565
Housing units251,530-56.7%580,772

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026; US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. The difference column is computed here: the first county's figure against the second, expressed as a percentage of the second. The change-since-2020 row is the exception: two growth rates differ in percentage points (pp), not percent. Retrieved 30 August 2026.

What the numbers say

  • Suffolk County holds about 2.4 times the population of Western Connecticut Planning Region: 1,546,090 against 640,482.
  • Suffolk County covers more ground, at 910.9 square miles against 532.1.
  • Suffolk County is the more crowded of the two, at 1,697 people per square mile against 1,204.
  • Median household income is higher in Suffolk County, by 2,498 dollars a year.
  • Since 2020, Western Connecticut Planning Region has grown by 3.5% and Suffolk County has grown by 1.6%.
  • They share 7.6 mi of common border, which the Census Bureau publishes in its county adjacency file and which almost no other county reference presents.

Full pages

Want a different pair? Compare any two of the 3,144 US counties.

Rebuilt from source data 30 August 2026. How these figures are produced.