San Marcos, Texas

San Marcos population, 2020 to 2024

San Marcos added 6,092 residents from July 2020 to July 2024, a change of +8.9%. In the latest year it moved by +2,383. Among 384 Texas places of 5,000 or more, that growth ranks 127th; the median place changed by +4.5%. The median place of 5,000+ in Texas has 15,345 people, so San Marcos is 4.8 times that size.

San Marcos covers 39.93 square miles of land and 0.13 of water, for 1,861 people per square mile of land. The median Texas place of 5,000+ has 1,561, so San Marcos is denser than the typical town.

What county San Marcos is in

All of San Marcos's residents live in Hays County, which had 292,029 residents in 2024. San Marcos holds 25.4% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in San Marcos

2 ZIP Code Tabulation Areas (ZCTAs) overlap San Marcos by at least 10% of the ZCTA's or the city's land: 78656, 78666. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where San Marcos is

The Census internal point of San Marcos is at 29.873600, -97.936700. Austin, the capital, is 30.1 miles NNE in a straight line. The nearest larger place is New Braunfels, TX (116,477 people), 16.1 miles away.

Daylight in San Marcos

At 29.87° N, San Marcos gets about 14 h 04 min of daylight around the June solstice and 10 h 13 min around the December solstice, a swing of 3 h 51 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near San Marcos

The eight nearest incorporated places of 1,000+ in Texas, measured between internal points. The closest is Martindale, 6.2 miles away, with 1,266 people.