Jefferson County, Idaho Demographics 2026

Population Overview

Jefferson County is located in Idaho with a total population of 32,234. It is the 12th most populous county out of 44 in Idaho.

Age Demographics

The median age in Jefferson County is 32.3 years. This is 13% lower than the state median of 37.1 years. With 32.9% of the population under 18, Jefferson County has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Jefferson County is $82,952. This is 11% higher than the state median of $74,636. Compared to the national median of $78,538, household income here is 6% higher. The poverty rate stands at 9.2%. This is 13% lower than the state poverty rate of 10.6%. The unemployment rate is 2.5%. This is 33% lower than the state rate of 3.7%. The median home value is $335,000. Housing costs are 11% lower than the state median of $376,000. The home-value-to-income ratio is 4.0x. 82.4% of occupied housing units are owner-occupied. This homeownership rate is 14% higher than the state average of 72.4%.

Race & Ethnicity

Jefferson County has a predominantly White (non-Hispanic) population, comprising 86.1% of all residents. Hispanic or Latino residents account for 10.8%. The Black or African American population (0.1%) is well below the state average of 0.7%. The Asian population (0.1%) is well below the state average of 1.3%.

Education

27.2% of residents aged 25 and older hold a bachelor's degree or higher. This is 13% lower than the state rate of 31.2%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 93.3%.