78666 ZIP Code
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ZIP code 78666 covers San Marcos, Texas, with a population of about 87,775 and a median household income of $55,478.
- Population
- 87,775456 per square mile
- Median age
- 2711.7 points below the US average
- Median household income
- $55,47827% below the Texas median
- Poverty rate
- 23.3%10.9 points above the US average
- Typical home value
- $314,817down 4.3% in five years
- Median rent
- $1,294about the Texas median
- Degree or higher
- 34.6%about the US average
- Homeownership
- 38.4%26.6 points below the US average
- Time zone
- Central UTC-06:00observes daylight saving time
- Businesses
- 1,839
Where 78666 is
San Marcos, Texas — the area the Census Bureau draws for this ZIP code. ZIP codes are sets of delivery routes rather than areas, so this is the Census approximation of one, not a Postal Service boundary.
People and households
American Community Survey 2019–2023 five-year estimates
| Population | 87,775 |
|---|---|
| Median age | 27 |
| Family households | 48.8% |
| Born outside the US | 7.8% |
| Speaks a language other than English at home | 27.2% |
| White (non-Hispanic) | 44.7% |
| Black (non-Hispanic) | 4.9% |
| Asian (non-Hispanic) | 1.7% |
| Hispanic or Latino | 43.8% |
| Veterans | 4.8% |
Income and poverty
American Community Survey 2019–2023 five-year estimates
| Median household income | $55,478 |
|---|---|
| Income per person | $28,813 |
| Poverty rate | 23.3% |
| Households on SNAP or cash assistance | 9.7% |
Household income distribution
| Under $10k | |
|---|---|
| $10–15k | |
| $15–20k | |
| $20–25k | |
| $25–30k | |
| $30–35k | |
| $35–40k | |
| $40–45k | |
| $45–50k | |
| $50–60k | |
| $60–75k | |
| $75–100k | |
| $100–125k | |
| $125–150k | |
| $150–200k | |
| $200k or more |
Income as declared to the IRS
Filed returns rather than survey responses, so this counts tax units and not households.
| Tax returns filed | 36,290 |
|---|---|
| Mean adjusted gross income | $65,196 |
| Returns declaring $200,000 or more | 3.8% |
| Returns, under $25k | 34.3% |
| Returns, $25k–$50k | 28.4% |
| Returns, $50k–$75k | 14.2% |
| Returns, $75k–$100k | 7.7% |
| Returns, $100k–$200k | 11.6% |
| Returns, $200k or more | 3.8% |
Housing
American Community Survey 2019–2023 five-year estimates
| Median home value | $271,900 |
|---|---|
| Median gross rent | $1,294 |
| Rent as a share of household income | 37.2% |
| Owner-occupied | 38.4% |
| Vacant homes | 6.9% |
| Median year built | 1997 |
What the homes are
| Detached house | |
|---|---|
| Attached house | |
| 2 to 4 units | |
| 5 to 19 units | |
| 20 or more units | |
| Mobile home | |
| Boat, RV or van |
Home values and rents today
Zillow Home Value Index and Zillow Observed Rent Index, courtesy of Zillow. Monthly and current, where the Census figures above are a five-year average and are capped at $2,000,000.
| Typical home value | $314,817as of 2026-07 |
|---|---|
| Typical home value, 1 year | down 3.6% |
| Typical home value, 5 years | down 4.3% |
| Typical home value, 10 years | up 45.8% |
| Typical asking rent | $1,388as of 2026-07 |
| Typical asking rent, 1 year | down 2.5% |
| Typical asking rent, 5 years | up 7.3% |
| Typical asking rent, 10 years | up 30.5% |
$168,304 in 2007 to $314,817 in 2026.
$1,063 in 2016 to $1,388 in 2026.
Work, commuting and education
American Community Survey 2019–2023 five-year estimates
| Unemployment rate | 5.6% |
|---|---|
| Bachelor's degree or higher | 34.6% |
| High school diploma or higher | 89.3% |
| Works from home | 9.4% |
| Drives to work alone | 72.3% |
| Takes public transport | 1% |
| Commutes 45 minutes or more | 18.2% |
Health
CDC PLACES 2025 release, model-based estimates. These are modelled small-area estimates for adults, not counts of diagnosed cases.
| Obesity | 34.4% 1 pts above the national average of 33.4% |
|---|---|
| Diagnosed diabetes | 9.3% 2.7 pts below the national average of 12% |
| Currently smokes | 11.4% 1.8 pts below the national average of 13.2% |
| High blood pressure | 25.7% 8.4 pts below the national average of 34.1% |
| Fair or poor general health | 21.6% 1.3 pts above the national average of 20.3% |
| No health insurance (18–64) | 20.1% 8.8 pts above the national average of 11.3% |
| Depression | 24.8% 2.9 pts above the national average of 21.9% |
| No leisure-time physical activity | 26% 0.6 pts above the national average of 25.4% |
| Arthritis | 16.3% 8.8 pts below the national average of 25.1% |
| Binge drinking | 19.1% 3.1 pts above the national average of 16% |
| Taking blood pressure medication | 65.3% 9.4 pts below the national average of 74.7% |
| Cancer (non-skin) | 4.4% 3.3 pts below the national average of 7.7% |
| Current asthma | 10.3% same as the national average of 10.4% |
| Coronary heart disease | 4.3% 1.9 pts below the national average of 6.2% |
| Routine check-up in past year | 69% 7.7 pts below the national average of 76.7% |
| Cholesterol screening | 76.3% 9.6 pts below the national average of 85.9% |
| Cognitive disability | 19.7% 4.9 pts above the national average of 14.8% |
| Colorectal screening | 60.2% 4.1 pts below the national average of 64.3% |
| COPD | 4.9% 1.7 pts below the national average of 6.6% |
| Visited a dentist | 51.1% 10.2 pts below the national average of 61.3% |
| Any disability | 33.1% 2.4 pts above the national average of 30.7% |
| Hearing disability | 5.4% 1.3 pts below the national average of 6.7% |
| High cholesterol | 28.3% 7.9 pts below the national average of 36.2% |
| Independent living disability | 9.9% 1.5 pts above the national average of 8.4% |
| Mammography use | 70.3% 5.6 pts below the national average of 75.9% |
| Poor mental health (14+ days) | 21.2% 4.4 pts above the national average of 16.8% |
| Mobility disability | 11.1% 2.9 pts below the national average of 14% |
| Poor physical health (14+ days) | 12.5% 1 pts below the national average of 13.5% |
| Self-care disability | 3.5% 0.5 pts below the national average of 4% |
| Sleeps under 7 hours | 36.5% same as the national average of 36.4% |
| Stroke | 2.3% 1.1 pts below the national average of 3.4% |
| All natural teeth lost | 13.5% 0.5 pts above the national average of 13% |
| Vision disability | 6.4% 0.8 pts above the national average of 5.6% |
Business and employment
Census ZIP Code Business Patterns 2022
| Business establishments | 1,839 |
|---|---|
| People employed | 33,361 |
| Annual payroll | $1,323,048,000 |
Natural hazard risk
FEMA National Risk Index, estimated for this ZIP code from census tract data — the NRI is not published per ZIP.
| Overall risk | Higher than 67.2% of US census tracts |
|---|---|
| FEMA rating | Very Low to Very High across the 27 census tracts this ZIP code covers |
| Expected annual loss | 63.7 out of 100 |
| Community resilience | 43.7 out of 100 |
By hazard
Score is out of 100 and is the area-weighted average across the census tracts this ZIP code covers. The rating beside it is the highest any one of those tracts carries.
| Hail | 89.1Very High at its worst in this ZIP code |
|---|---|
| Wildfire | 87.5Relatively Moderate at its worst in this ZIP code |
| Lightning | 87.4Very High at its worst in this ZIP code |
| Tornado | 87.4Very High at its worst in this ZIP code |
| Winter weather | 85.1Very High at its worst in this ZIP code |
| Heat wave | 74.9Relatively High at its worst in this ZIP code |
| River flooding | 73.8Very High at its worst in this ZIP code |
| Strong wind | 71Relatively High at its worst in this ZIP code |
| Cold wave | 63.4Relatively High at its worst in this ZIP code |
| Drought | 59.5Relatively Moderate at its worst in this ZIP code |
| Landslide | 52.4Relatively Low at its worst in this ZIP code |
| Hurricane | 52.1Relatively Low at its worst in this ZIP code |
| Ice storm | 46.6Relatively Low at its worst in this ZIP code |
| Earthquake | 6.4Very Low at its worst in this ZIP code |
Compared with Texas and the United States
State and national columns are figures for those areas, not for this ZIP code. American Community Survey 2019–2023 five-year estimates
| This ZIP | Texas | United States | |
|---|---|---|---|
| Median household income | $55,478 | $76,292 | $78,538 |
| Income per person | $28,813 | $39,446 | $43,289 |
| Poverty rate | 23.3% | 13.8% | 12.4% |
| Median home value | $271,900 | $260,400 | $303,400 |
| Median gross rent | $1,294 | $1,339 | $1,348 |
| Homeownership | 38.4% | 62.6% | 65% |
| Bachelor's degree or higher | 34.6% | 33.1% | 35% |
| Unemployment rate | 5.6% | 5.1% | 5.2% |
| Works from home | 9.4% | 12.8% | 13.5% |
| Born outside the US | 7.8% | 17.2% | 13.9% |
| Median age | 27 | 35.5 | 38.7 |
Climate
NOAA US Climate Normals 1991-2020, from the nearest weather station with a full year of records. The station and its distance are named above, because a station forty kilometres away describes somewhere else.
| Weather station | SAN MARCOS, TX US1.2 km away |
|---|---|
| Rain in a year | 37 in |
Average high and low by month
| January | 62.3°F / 38.9°F2.41 in rain |
|---|---|
| February | 66.6°F / 42.4°F1.73 in rain |
| March | 73.1°F / 49.5°F2.76 in rain |
| April | 79.8°F / 56.3°F3.2 in rain |
| May | 86.2°F / 64.9°F4.53 in rain |
| June | 92.4°F / 71.7°F3.57 in rain |
| July | 95.7°F / 73.4°F2.21 in rain |
| August | 96.8°F / 73.7°F2.6 in rain |
| September | 90.5°F / 68.5°F4.03 in rain |
| October | 82.1°F / 58.1°F4.41 in rain |
| November | 71.5°F / 48.3°F2.69 in rain |
| December | 63.7°F / 40.8°F2.41 in rain |
Access to food
USDA Food Access Research Atlas, estimated for this ZIP code from census tract data. Each figure is the share of the ZIP code's land area that falls in a tract carrying that flag.
| Low income and far from a supermarket | 8% of this ZIP code's area |
|---|---|
| Far from a supermarket | 8% of this ZIP code's area |
| No vehicle and far from a supermarket | 49% of this ZIP code's area |
School districts
NCES Geographic Relationship File 2025, which states the association between each district and each ZIP code tabulation area directly. Elementary and secondary districts can cover the same ground, so shares need not total 100%.
This ZIP code is served by 5 school districts, so the address decides which one, not the ZIP code.
| San Marcos Consolidated Independent School District | 69.1% of this ZIP code's land area |
|---|---|
| Hays Consolidated Independent School District | 11.1% of this ZIP code's land area |
| Wimberley Independent School District | 8.6% of this ZIP code's land area |
| Navarro Independent School District | 6.9% of this ZIP code's land area |
| Comal Independent School District | 4.3% of this ZIP code's land area |
Community and walkability
CDC/ATSDR Social Vulnerability Index 2022 and the EPA National Walkability Index, both estimated for this ZIP code from census tract data. Vulnerability figures are national percentile ranks, not measurements.
| Overall social vulnerability | 58more vulnerable than 58% of US census tracts |
|---|---|
| Socioeconomic status | 61more vulnerable than 61% of US census tracts |
| Household characteristics | 30more vulnerable than 30% of US census tracts |
| Racial and ethnic minority status | 56more vulnerable than 56% of US census tracts |
| Housing type and transport | 64more vulnerable than 64% of US census tracts |
| Walkability | 5.9 out of 20Below average |
Nearby ZIP codes
The closest ZIP codes by centre point, which is not the same as sharing a border.
| 78655 Martindale, TX | 9.5 km away |
|---|---|
| 78656 Maxwell, TX | 12.3 km away |
| 78670 Staples, TX | 16.5 km away |
| 78640 Kyle, TX | 17 km away |
| 78622 Fentress, TX | 20.6 km away |
| 78667 San Marcos, TX | 20.8 km away |
| 78130 New Braunfels, TX | 21.3 km away |
| 78676 Wimberley, TX | 23.6 km away |
Location, counties and time zone
County shares from Census 2020 ZCTA relationship files. Time zone from the USDOT National Transportation Atlas, which renders the boundaries written into 49 CFR Part 71.
| Hays County | 77.9% of this ZIP code's land area |
|---|---|
| Guadalupe County | 15.7% of this ZIP code's land area |
| Comal County | 4.3% of this ZIP code's land area |
| Caldwell County | 2% of this ZIP code's land area |
| Time zone | Central (UTC-06:00 standard) |
| Daylight saving time | Observed |
| Land area | 192.39 sq mi |
| Water area | 1.02 sq mi |
| Population density | 456 people per sq mi |
| Latitude, longitude | 29.8754, -97.9404 |
Figures are published for this ZIP code or its Census tabulation area unless a section says otherwise. Estimates whose margin of error made them unreliable are omitted rather than shown. Sources: US Census Bureau, CDC, IRS.