ZIP code · Round Rock · Texas · United States
ZIP code 78665 — Round Rock
ZIP code 78665 serves Round Rock, Texas.
- Postal code
- 78665Single source Value from one source, not cross-checked.
- City
- Round Rock
- County
- Williamson FIPS 48491
- State
- Texas
- Country
- United States
- Coordinates
- 30.5145, -97.6680 — precision precise (locality)
View on OpenStreetMap - Population
- 64,087 (ZCTA, ACS 5-year)
- Population density
- 2,662 / sq mi
- Land area
- 24.1 sq mi (62.4 km²) (ZCTA, ACS 5-year)
- Median household income
- $117,240
- Per-capita income
- $52,667
- Median age
- 36.1
- Households
- 23,318
- Housing units
- 24,678
- Median home value
- $438,700
- Median gross rent
- $1,945 / month
- Congressional districts
- TX-31 (also TX-17) (119th Congress)
- USDA hardiness zone
- 9a (20 to 25 °F)Planting / growing zone from the 2023 USDA Plant Hardiness Zone Map: average annual extreme minimum temperature, 1991–2020.
- Time zone
- America/Chicago (UTC−6 / UTC−5 DST)
Tools: compare 78665 with another ZIP · ZIPs within 25 miles · distance from 78665
Map of ZIP code 78665
Climate — monthly normals
Warmest month Aug (avg high 96°F), coldest Jan (avg low 38°F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 60 | 65 | 72 | 79 | 84 | 92 | 96 | 96 | 89 | 80 | 69 | 61 |
| Avg low °F | 38 | 41 | 48 | 55 | 64 | 70 | 73 | 72 | 67 | 57 | 47 | 39 |
| Precip in | 2.6 | 2.0 | 3.0 | 2.3 | 4.1 | 4.4 | 2.8 | 2.3 | 3.4 | 4.6 | 2.8 | 2.8 |
NOAA 1991–2020 climate normals from the nearest station: AUSTIN GREAT HILLS (9.1 mi) · NOAA NCEI
Places in ZIP 78665
- 14 schools
- 2 colleges & universities
- 7 hospitals & clinics
- 9 doctors & dentists
- 4 pharmacies
- 2 supermarkets
- 71 restaurants & cafés
- 3 bars & pubs
- 38 parks
- 52 playgrounds
- 17 gyms & sports centres
- 2 post offices
- 8 places of worship
- 13 banks
- 18 gas stations
- 5 EV charging stations
- 6 police & fire stations
Places mapped inside this ZIP’s ZCTA area in OpenStreetMap. OSM is community-maintained: counts reflect what has been mapped, and completeness varies by area — treat them as at-least figures. © OpenStreetMap contributors (ODbL) · Methodology
About this page
US ZIP codes have five digits. They are postal routing areas, not administrative boundaries: a ZIP can span more than one city or county, and the city shown is the primary USPS name for that code.
GeoNames · U.S. Census Bureau (ACS) · U.S. Census Bureau · NOAA NCEI · usda-phzm. Data generated on 2026-08-21. Methodology · Report an error on this page