Jefferson County, Idaho Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Jefferson County, ID Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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B
Health Around averageHealthier than 85% of counties in Idaho
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B
Income Around averageAmong the top 5 wealthiest counties in Idaho
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D
Education Well below averageBetter educated than 70% of counties in Idaho
Source: Map AI Methodology
Population: density and quick facts
| Metric | Jefferson County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Population | 33,153 | 1,929,983 | 337,468,954 |
| Population density (per sq mi) | 30.0 | 23.1 | 86.4 |
| Population growth (%/yr) | 2.57% | 2.12% | 0.59% |
| Median age | 31.0 | 38.7 | 37.3 |
| Households | 10,199 | 712,816 | 130,235,071 |
Population in Jefferson County grew by 44.9% from 2009 to 2024, reaching 33,153 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Jefferson County is Gen Z, aged 13–28, at 23.3% of residents. That is 0.5 points above Idaho as a whole.
- Gen Z 13–28 7,731 23.3% +0.5 pts
- Millennials 29–44 6,892 20.8% on par
- Gen X 45–60 5,704 17.2% -2.0 pts
- Boomers 61–79 4,213 12.7% -3.3 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Idaho, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 49.2% of the people living in Jefferson County and men 50.8%.
- Women 49.2% Idaho 49.6%
- Men 50.8% Idaho 50.4%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Jefferson County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Jefferson County has a the economy index of B, which means it is quite prosperous.
| Metric | Jefferson County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Median household income | $86,175 | $78,141 | $80,455 |
| Income growth (%/yr) | 5.86% | 5.97% | 4.80% |
| Unemployment rate | 2.7% | 3.7% | 5.2% |
The median household income in Jefferson County is about 10% higher than in Idaho.
Housing
| Metric | Jefferson County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Median home price | $169,582 | $394,140 | $248,835 |
| Median rent | $1,137 | $1,236 | $1,407 |
| Homeownership rate | 83.0% | 72.3% | 65.2% |
The median home price in Jefferson County is about 12.4 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $1,137 per month for that long.
Commute Time & Mobility
Commuters in Jefferson County spend about 44 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 184 hours, about 7.7 full days, spent commuting.
| Metric | Jefferson County | Idaho Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 22.1 | 18.0 | 22.4 |
| Round-trip commute (min) | 44.2 | 35.9 | 44.8 |
| Yearly time spent (hours) | 184 | 150 | 187 |
| Estimated yearly cost | $5,714 | $4,641 | $5,790 |
| Work from home | 7.6% | 13.3% | 15.0% |
| Highway traffic (vehicles/day) | 4,082 | 4,714 | 8,813 |
| Local road traffic (vehicles/day) | 838 | 865 | 1,355 |
Fastest commutes among counties in
Idaho:
Custer County (8.9 min), Lemhi County (11.6 min), Madison County (12.0 min).
Slowest:
Camas County (49.5 min), Boise County (38.0 min), Lincoln County (32.0 min).
The average commute time in Jefferson County is 22 minutes, longer than the 18 minutes in Idaho.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Jefferson County has a education index of D, which means it is barely educated.
| Metric | Jefferson County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 23.9% | 27.1% | 31.6% |
| Average household size | 3.23 | 2.64 | 2.53 |
Highest education index among counties in
Idaho:
Latah County (0.4), Teton County (0.3), Ada County (0.3).
Lowest:
Clark County (0.1), Owyhee County (0.2), Lincoln County (0.2).
Health
Jefferson County has a health index of B, which means it is quite healthy.
| Metric | Jefferson County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 80.7 | 79.5 | 78.3 |
| Self-rated poor health | 12.6% | 15.6% | 16.3% |
| Smokers | 15.8% | 17.6% | 19.0% |
Highest health index among counties in
Idaho:
Madison County (0.8), Latah County (0.8), Ada County (0.8).
Lowest:
Shoshone County (0.8), Washington County (0.8), Lincoln County (0.8).
Jefferson County, ID Compared With Nearby Counties
Jefferson County, ID is the smallest of the 4 counties compared here, 33,153 residents against a local median of 54,618. Where Jefferson County, ID breaks from the counties next to it is median home price, sitting 55% below the local median of $378,543 at $169,582.
Commute tells the same story from another angle: 22.1 min against a local median of 16.0 min, 38% above it. The one measure here that carries a verdict is commute, and at 38% above the local median it puts Jefferson County, ID at the weaker end of the local range. The counties themselves spread $143,744 on median home price, so Jefferson County, ID sits at one end of an already wide local range rather than apart from it. Jefferson County, ID has the 4th highest median home price of the 4 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Jefferson County, ID | 33,153 | $86,175 #1/4 | $169,582 #4/4 | 22.1 min #4/4 |
| Bingham County, ID | 49,662 | $77,597 | $439,475 | 18.3 min |
| Madison County, ID | 54,618 | $60,340 | $295,731 | 12.0 min |
| Bonneville County, ID | 129,518 | $80,129 | $378,543 | 16.0 min |
Frequently Asked Questions
Common questions about Jefferson County, Idaho.
How many people live in Jefferson County, Idaho?
About 33,153 people live in Jefferson County, Idaho, in 10,199 households of 3.2 people on average. The median age is 31.0, so residents are younger than the U.S. median of 37.3 by about 6 years.
How densely populated is Jefferson County, Idaho?
Averaged over its land area, Jefferson County, Idaho has 30 people per square mile, a density typical of rural areas. That is about 35% of the U.S. average of 86.
Is Jefferson County, Idaho an affordable place to live?
The median home costs 2.0 times the median household income ($169,582 against $86,175), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $1,137 a month takes about 16% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
Is it hard to find a job in Jefferson County, Idaho?
Unemployment in Jefferson County, Idaho is only 2.7%, well below the U.S. rate of 5.2%, a sign of a tight labor market where employers compete for workers.
What share of adults in Jefferson County, Idaho have a college degree?
23.9% of adults in Jefferson County, Idaho hold a bachelor's degree or higher (about 1 in 4), well below the U.S. share of 31.6%.
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