South Jefferson, Thousand Island - Seaway, NY demographics:
population, income, and more

Total population
11,918
1.1% year-over-year change
Median household income
$81,059/yr
-3.2% year-over-year change
Housing units
7,008
3.3% year-over-year change

South Jefferson population

How many people live in South Jefferson

South Jefferson is home to 11,918 residents, according to the most recent Census data. Gender-wise, 52.4% of South Jefferson locals are male, and 47.6% are female.

Total population
11,918
1.1% year-over-year change
Gender ratio
Male
52.4%
6,249
Female
47.6%
5,669
Value Percent YoY change
Male 6,249 52.4% 1.6%
Female 5,669 47.6% 0.6%
A higher population often means more rental variety and livelier areas. The gender balance—how many men live here compared to women—can reveal a lot about the community and the lifestyles of its residents. Use this info to get a sense of the area's pace and personality.

Age demographics

The median age in South Jefferson is 42, with the population distributed as follows: about 19.9% are children under 15, then 12% are in the 15 to 24 age group. Adults between 25 and 44 make up 24.1% of the population, while another 24.8% fall into the 45 to 64 bracket. Finally, around 19.2% are 65 or older.

Median age
42.3
Age breakdown
Under 15
19.9%
15 to 24
12%
25 to 44
24.1%
45 to 64
24.8%
Over 65
19.2%
Value Percent YoY change
Under 15 2,372 19.9% -1.3%
15 to 24 1,430 12% 4.0%
25 to 44 2,876 24.1% 2.8%
45 to 64 2,950 24.8% -1.5%
Over 65 2,291 19.2% 3.5%
The age composition helps you get insight into who lives in the area. A younger population might mean a more active, fast-paced vibe, while an older one could suggest a quieter, slower lifestyle. If there's a balanced makeup, you’re likely to find a variety of services, housing types, and community spaces that cater to different life stages.

Racial makeup

In South Jefferson, 97% of the population are US-born citizens, while 1.1% have gained naturalized citizenship. At the same time, 1.9% of residents are non-citizens. As for race, 91.8% of locals are Caucasian, 2.4% are African American and 0.3% have Asian roots. There’s also a share of 4.9% that includes residents with two or more races.

Citizenship
U.S.-born citizens
97%
Non-U.S.-born citizens
1.1%
Non-citizens
1.9%
Value Percent YoY change
U.S.-born citizens 11,556 97% 1.2%
Non-U.S.-born citizens 133 1.1% -22.2%
Non-citizens 229 1.9% 17.4%
Racial breakdown
White
91.8%
Black or African American
2.4%
American Indian and Alaska Native
0.1%
Asian
0.3%
Native Hawaiian and other Pacific Islander
0%
Two or more races
4.9%
Other
0.4%
Value Percent
White 10,947 91.8%
Black or African American 283 2.4%
American Indian and Alaska Native 14 0.1%
Asian 39 0.3%
Two or more races 582 4.9%
Other 53 0.4%

Households in South Jefferson

A peek inside South Jefferson households

South Jefferson has 4,859 households, with an average of 2 members in each. Of these, 71.5% are families, while the remaining 28.5% are made up of individuals living alone or with non-relatives, such as roommates.

Households stats

Total households
4,859
5.5% year-over-year change
Average people per household
2
Non-family households
1,383
Family households
3,475
Value Percent YoY change
Non-family households 1,383 28.5% 8.7%
Family households 3,475 71.5% 4.3%
The mix between family and non-family households gives a glimpse into daily life. A higher percentage of families might mean more parks and schools, while more non-family setups can mean flexible housing and diverse living styles. For renters, this can signal what kinds of homes are common and can help you figure out if the area matches your lifestyle.

Housing in South Jefferson

The housing landscape of South Jefferson

South Jefferson's housing consists of 7,008 units, with 76% being detached single-family homes ideal for those wanting space. Attached options, including duplexes and townhouses, make up 0.6% and offer a more compact, shared living style. Then there are the multifamily buildings in the area, and for those seeking flexibility, non-traditional options like mobile homes account for 13.4% of the housing landscape.

Housing units
7,008
3.3% year-over-year change
Housing types
Value Percent
1 unit, detached 5,330 76%
1 unit, attached 43 0.6%
2 units 384 5.5%
3 or 4 units 73 1%
5 to 9 units 88 1.3%
10 to 19 units 18 0.3%
20 to 49 units 57 0.8%
50 or more units 56 0.8%
Mobile home 943 13.4%
Boat, RV, van, etc. 17 0.2%
Homes built since 2020
103
6.2% year-over-year change

The age of buildings in South Jefferson

In South Jefferson, the median construction year is 1970. About 34% of homes were built before the 1940s, with another 3.1% going up by 1949. Most development happened in the second half of the 20th century. Then, 10.8% of homes were added from 2000 to 2009, 7% between 2010 and 2019, and 1.5% are part of the newest wave of development.

Construction year breakdown by decade
Value Percent YoY change
Built in 1939 or earlier 2,383 34% 8.1%
Built between 1940 and 1949 218 3.1% -4.4%
Built between 1950 and 1959 419 6% -8.1%
Built between 1960 and 1969 434 6.2% -14.6%
Built between 1970 and 1979 766 10.9% 2.3%
Built between 1980 and 1989 658 9.4% 5.6%
Built between 1990 and 1999 772 11% -9.6%
Built between 2000 and 2009 760 10.8% 10.1%
Built between 2010 and 2019 494 7% 31.4%
Built in 2020 or later 103 1.5% 6.2%
As a renter, knowing when homes were built helps you understand the potential condition and design of rental units. Newer builds may have more contemporary layouts, while older homes can offer character or larger lots, depending on the area.

South Jefferson occupancy rates

Out of the 4,859 occupied housing units in South Jefferson, 79.5% are owner-occupied, while 20.5% are lived in by tenants. Meanwhile, 30.7% of all homes on the local market sit vacant.

Occupied housing units
4,859
5.5% year-over-year change
Occupancy breakdown
Renter occupied
995
Owner occupied
3,864
Value Percent YoY
change
Renter occupied 995 20.5% 14.8%
Owner occupied 3,864 79.5% 3.4%
Unoccupied housing units
30.7%
Unoccupied housing units refer to homes that are currently without residents—whether they're waiting for renters or owners, used seasonally, or simply unclaimed. A higher share of empty homes may mean more housing availability, while a low number can reflect a tighter market with more competition. This, along with the renter-vs.-owner mix, helps paint a clearer picture of what types of housing and services are likely to be available in the area.

South Jefferson housing costs

Housing costs in South Jefferson come to a median of $1,006 per month, while tenants specifically pay a median gross rent of $950.

Median housing costs per month
$1,006/month
This figure sums up typical monthly housing costs for all households in the area. If you own, it includes mortgage payments in addition to property taxes, insurance and HOA fees. If you rent, it accounts for rent plus extras like utilities. It’s useful for seeing how local living expenses stack up compared to other places.
Median gross rent in South Jefferson
$950/month
Gross rent gives a more complete look at what renters actually pay, including not just base rent, but also utilities and fees. It’s a key number for evaluating rental affordability in your area of interest and understanding how it compares to nearby locations.

Education in South Jefferson

South Jefferson education at a glance

About 40.7% of the population in South Jefferson went to high school, while 20.9% pursued college studies. Another 14.9% earned an associate degree and 11.2% hold a bachelor’s. Meanwhile, 11% went even further, earning a master’s or doctorate.

Education level
Value Percent YoY change
No high school 116 1.3% 1.8%
High school diploma 3,668 40.7% 2.1%
College diploma 1,882 20.9% 5.3%
Associate degree 1,341 14.9% -0.9%
Bachelor's degree 1,012 11.2% -1.6%
Graduate degree 994 11% 1.8%
A community’s education mix can offer insights into the local economy and housing market. Higher levels of education often align with more job opportunities and stable incomes, which can increase demand for homes and influence both rent prices and rental availability.

Income in South Jefferson

How much people earn in South Jefferson

The average annual household income in South Jefferson was $95,857 in 2024, the most recent annual data available, according to the U.S. Census Bureau. This marked a +2% change from the previous year. At the same time, the median income stood at $81,059, reflecting a -3.2% shift over the same period.

Average household income in South Jefferson
$95,857/year
2.0% year-over-year change
Median household income in South Jefferson
$81,059/year
-3.2% year-over-year change

South Jefferson income by age

In South Jefferson, households led by residents aged 25 to 44 — usually in the early to mid stages of their careers — have a median income of $93,125. Those with someone between 45 and 64 in charge, often well established professionally, earn $95,528 overall. Younger households, where the main provider is under 25 and just starting out, report a median income of $43,973, while those led by someone over 65, many of whom may be retired, have about $57,125 in earnings. Overall, 90.8% of the locals in this community live above the poverty line.

Income breakdown by age
Value YoY change
Under 25 $43,973 51.0%
25 - 44 $93,125 -3.5%
45 - 64 $95,528 4.0%
Over 65 $57,125 6.8%
Above poverty level
10,657
Below poverty level
1,073
Value Percent YoY
change
Above poverty level 10,657 90.8% 2.3%
Below poverty level 1,073 9.2% -5.5%

Employment in South Jefferson

Workforce and job types in South Jefferson

77% of the working population are employed in professional or administrative positions, while 23% are in hands-on or service-based jobs. Also, 8% run their own businesses, 60.1% are employed by private companies, and 24.9% work in the public sector.

Workforce demographics

White collar
4,326
Blue collar
1,290
Value Percent YoY change
White collar 4,326 77% 1.3%
Blue collar 1,290 23% -1.6%
Employer type
Self employees
8%
Private companies
60.1%
Governmental workers
24.9%
Not for profit companies
7.1%
Value Percent YoY change
Self employees 448 8% 2.8%
Private companies 3,374 60.1% 0.2%
Governmental workers 1,396 24.9% 1.3%
Not for profit companies 398 7.1% -0.8%

Transportation in South Jefferson

How people get around in South Jefferson

In South Jefferson, the average commute time is 58 minutes. Commuting methods vary: 94.1% of residents travel by personal vehicle and 5.9% prefer to walk, while the remaining share relies on public transit or on two wheelers to get from A to B.

Commute time
58 min
107.1% year-over-year change
Means of transportation
Value Percent YoY change
Car 4,686 94.1% -2.5%
Bicycle 1 0% -90.0%
Walk 292 5.9% 61.3%
Understanding how locals get to work can help you plan your own routine. High car usage might mean you’ll need a vehicle, while strong public transit or walkability could save you the hassle. Commute times also play a big role in quality of life—shorter trips can give you more time for the things you enjoy.

What is the median and average household income in South Jefferson by zipcode?

Zipcode Population Number of households Median income Average income
13674 178 69 $0 $76,461
13682 854 335 $79,821 $92,601
13605 5,259 2,189 $70,045 $103,162
13606 2,468 894 $88,977 $101,269
13659 386 155 $63,125 $80,715
13661 1,908 723 $82,297 $91,293
13650 1,236 598 $94,318 $115,794
13651 147 85 $116,705 $126,152
13636 141 63 $58,882 $74,137

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FAQs about South Jefferson demographics 

What is the total population of South Jefferson?

South Jefferson has a total population of 11,918 residents, according to the latest release from the U.S. Census Bureau: the 2019-2023 American Community Survey (ACS) 5-year estimates. This figure changed by +1.1% compared to a year ago.

What is the gender ratio in South Jefferson?

The gender ratio in South Jefferson is as follows:
  • 52.4% males (6,249 residents)
  • 47.6% females (5,669 residents)

What is the median age in South Jefferson?

The median age in South Jefferson is 42.3.

What is the age distribution of the population in South Jefferson?

The age distribution in South Jefferson is as follows:
  • Under 15: 19.9% (2,372 residents)
  • Ages 15-24: 12% (1,430 residents)
  • Ages 25-44: 24.1% (2,876 residents)
  • Ages 45-64: 24.8% (2,950 residents)
  • Over 65: 19.2% (2,291 residents)

What is the racial and ethnic makeup of South Jefferson?

The racial and ethnic makeup of South Jefferson is as follows:
  • White: 91.8% (10,947 residents)
  • Black or African American: 2.4% (283 residents)
  • American Indian and Alaska Native: 0.1% (14 residents)
  • Asian: 0.3% (39 residents)
  • Native Hawaiian and Other Pacific Islander: 0% ( residents)
  • Two or More Races: 4.9% (582 residents)
  • Other: 0.4% (53 residents)

What percentage of the population in South Jefferson are U.S.-born citizens?

U.S.-born citizens represent 97% of the population in South Jefferson.

How many housing units are there in South Jefferson?

There are 7,008 housing units in South Jefferson, reflecting a +3.3% change compared to the previous year, according to the latest data from the U.S. Census Bureau.

How many households are in South Jefferson and what is the average household size?

South Jefferson has a total of 4,859 households, with an average of 2 people in each.

What is the median household income in South Jefferson?

South Jefferson has a median household income of $81,059, representing a -3.2% shift from the previous year, according to the U.S. Census Bureau.

What is the job market overview for South Jefferson?

Here’s a detailed breakdown of the local job market:

Job types:
  • White-collar workers: 77% (4,326 residents)
  • Blue-collar workers: 23% (1,290 residents)

Places of employment:
  • Self-employed: 8% (448 residents)
  • Private companies: 60.1% (3,374 residents)
  • Governmental workers: 24.9% (1,396 residents)
  • Not-for-profit companies: 7.1% (398 residents)

Data source & methodology

The demographic data on this page was sourced from the latest U.S. Census Bureau release—the 2019–2023 American Community Survey (ACS) 5-year estimates.

The information, issued annually, is compiled and published by the Point2Homes Research Team as soon as new data becomes available.

No representation, guarantee, or warranty is made concerning the accuracy or completeness of modified or aggregated information for particular areas.

Page last updated: September 2025