Demographics of Siskiyou County, California

Siskiyou County, California had 42,013 people on July 1, 2025, by the Census Bureau’s estimate: −1,970 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Siskiyou County, in four figures

42,013
Population: July 1, 2025, Vintage 2025 estimate.; −4.5%
Change since July 2020: −1,970 people.; 47.2 ±0.5
Median age: ACS 2020–⁠2024.; $59,095 ±$3,737
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Siskiyou County, California's population shrank 4.5% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Siskiyou County, California's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Siskiyou County, California's population shrank 4.5% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Siskiyou County, California's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	43,983	100.0	100.0
2021	44,058	100.2	100.2
2022	43,602	99.1	100.7
2023	42,856	97.4	101.6
2024	42,490	96.6	102.5
2025	42,013	95.5	103.1

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Population of Siskiyou County, California on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	43,983	−93	−57	0	−38
2021	44,058	+75	−263	+7	+322
2022	43,602	−456	−367	+23	−81
2023	42,856	−746	−208	+39	−582
2024	42,490	−366	−232	+51	−189
2025	42,013	−477	−281	+19	−217

Age, 2020–2024

The median age is 47.2 ±0.5: for men 45.6 ±0.3 and for women 49.2 ±0.5. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Siskiyou County by age, ACS 2020–2024
Age	People	Share	California	United States
Under 5	1,971 ±103	4.5% ±0.2	5.5% ±<0.1	5.6% ±<0.1
5 to 17	6,719 ±382	15.5% ±0.9	16.5% ±<0.1	16.3% ±<0.1
18 to 24	2,621 ±211	6.0% ±0.5	9.1% ±<0.1	9.1% ±<0.1
25 to 44	9,279 ±456	21.3% ±1.1	28.7% ±<0.1	26.9% ±<0.1
45 to 64	10,775 ±408	24.8% ±0.9	24.6% ±<0.1	24.8% ±<0.1
65 and over	12,101 ±526	27.8% ±1.2	15.7% ±<0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $59,095 ±$3,737, and income per person $36,529 ±$1,787, in 2024 dollars. The median is $99,122 ±$310 in California and $80,734 ±$166 in the United States.

Households by income

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Households in Siskiyou County by income, ACS 2020–2024
Household income	Households	Share	California	United States
Under $25,000	4,099 ±422	21.5% ±2.2	12.5% ±0.1	14.6% ±<0.1
$25,000 to $49,999	4,035 ±371	21.1% ±1.9	13.3% ±0.1	16.7% ±<0.1
$50,000 to $74,999	3,648 ±393	19.1% ±2.0	13.0% ±0.1	15.5% ±<0.1
$75,000 to $99,999	2,146 ±251	11.2% ±1.3	11.6% ±0.1	12.6% ±<0.1
$100,000 to $149,999	2,765 ±326	14.5% ±1.7	17.8% ±0.1	17.5% ±<0.1
$150,000 to $199,999	1,290 ±234	6.8% ±1.2	11.3% ±0.1	9.6% ±<0.1
$200,000 or more	1,096 ±226	5.7% ±1.2	20.5% ±0.1	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Siskiyou County by age, ACS 2020–2024
Age	Below poverty	Rate	California	United States
All ages	7,037 ±793	16.4% ±1.8	12.0% ±0.1	12.5% ±0.1
Under 18	1,749 ±310	20.5% ±3.4	15.0% ±0.1	16.1% ±0.1
18 to 59	3,273 ±438	17.1% ±2.2	11.0% ±0.1	11.6% ±0.1
60 and over	2,015 ±275	13.2% ±1.7	11.5% ±0.1	11.0% ±<0.1

Housing, 2020–2024

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Housing in Siskiyou County, ACS 2020–2024
Measure	Siskiyou County	California	United States
Housing units	23,088 ±51	14,644,735 ±1,665	143,775,355 ±10,234
Occupied	82.6% ±1.5	92.5% ±0.1	89.9% ±0.1
Vacant	17.4% ±1.5	7.5% ±0.1	10.1% ±0.1
Owner occupied	69.2% ±2.4	55.9% ±0.3	65.2% ±0.3
Renter occupied	30.8% ±2.1	44.1% ±0.2	34.8% ±0.1
Median home value	$309,500 ±$11,190	$734,700 ±$1,307	$332,700 ±$236
Median gross rent	$1,091 ±$73	$2,036 ±$5	$1,413 ±$2
Median year built	1976 ±1	1976 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Siskiyou County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	California	United States
Hispanic or Latino	5,860 ±0	13.5% ±<0.1	40.2% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	31,859 ±186	73.3% ±0.4	33.8% ±<0.1	57.4% ±<0.1
Black alone, not Hispanic	579 ±130	1.3% ±0.3	5.2% ±<0.1	11.9% ±<0.1
Asian alone, not Hispanic	784 ±122	1.8% ±0.3	15.3% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	1,195 ±158	2.7% ±0.4	0.3% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	174 ±54	0.4% ±0.1	0.3% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	80 to 272	0.2% to 0.6%	0.6% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	2,839 ±294	6.5% ±0.7	4.4% ±<0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Siskiyou County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	California	United States
Born in the state	27,305 ±840	62.8% ±1.9	56.5% ±0.1	57.3% ±<0.1
Born in another state	13,302 ±746	30.6% ±1.7	15.0% ±0.1	26.9% ±<0.1
Born a citizen outside the states	320 ±100	0.7% ±0.2	1.5% ±<0.1	1.7% ±<0.1
Born abroad	2,539 ±324	5.8% ±0.7	27.0% ±0.1	14.1% ±<0.1
Naturalized citizens	1,589 ±241	3.7% ±0.6	14.7% ±0.1	7.4% ±<0.1
Not citizens	950 ±226	2.2% ±0.5	12.3% ±0.1	6.8% ±<0.1

Siskiyou County among the counties of California

45th of 58 by population, July 2025. Every one is listed on the California page.

Counties of California near Siskiyou County in population, July 2025
County	July 2025	Change since 2020
San Benito County	70,082	+8.6%
Lake County	67,772	−0.6%
Tehama County	64,665	−1.7%
Tuolumne County	53,160	−4.0%
Calaveras County	46,605	+2.8%
Siskiyou County	42,013	−4.5%
Amador County	41,876	+3.2%
Glenn County	28,141	−2.6%
Lassen County	28,117	−13.1%
Del Norte County	26,410	−4.4%
Colusa County	21,836	−0.1%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026