ZIP code · Frederick · Maryland · United States
ZIP code 21704 — Frederick
ZIP code 21704 serves Frederick, Maryland.
- Postal code
- 21704Single source Value from one source, not cross-checked.
- City
- Frederick
- County
- Frederick FIPS 24021
- State
- Maryland
- Country
- United States
- Coordinates
- 39.3455, -77.3832 — precision precise (locality)
View on OpenStreetMap - Population
- 19,623 (ZCTA, ACS 5-year)
- Population density
- 737 / sq mi
- Land area
- 26.6 sq mi (69 km²) (ZCTA, ACS 5-year)
- Median household income
- $164,457
- Per-capita income
- $60,724
- Median age
- 38.4
- Households
- 6,136
- Housing units
- 6,230
- Median home value
- $585,900
- Median gross rent
- $2,395 / month
- Congressional district
- MD-6 (119th Congress)
- USDA hardiness zone
- 7a (0 to 5 °F)Planting / growing zone from the 2023 USDA Plant Hardiness Zone Map: average annual extreme minimum temperature, 1991–2020.
- Time zone
- America/New_York (UTC−5 / UTC−4 DST)
Tools: compare 21704 with another ZIP · ZIPs within 25 miles · distance from 21704
Map of ZIP code 21704
Climate — monthly normals
Warmest month Jul (avg high 89°F), coldest Jan (avg low 27°F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 43 | 48 | 55 | 69 | 77 | 85 | 89 | 87 | 80 | 69 | 56 | 47 |
| Avg low °F | 27 | 29 | 36 | 45 | 55 | 63 | 68 | 66 | 59 | 47 | 38 | 31 |
| Precip in | 2.6 | 3.0 | 3.7 | 3.5 | 4.0 | 4.3 | 3.9 | 2.9 | 5.8 | 3.3 | 2.7 | 4.0 |
NOAA 1991–2020 climate normals from the nearest station: FREDERICK POLICE BRKS (5.7 mi) · NOAA NCEI
Places in ZIP 21704
- 6 schools
- 2 hospitals & clinics
- 5 doctors & dentists
- 1 pharmacies
- 4 supermarkets
- 59 restaurants & cafés
- 1 bars & pubs
- 40 parks
- 15 playgrounds
- 9 gyms & sports centres
- 1 libraries
- 4 post offices
- 11 places of worship
- 9 banks
- 15 gas stations
- 4 EV charging stations
- 1 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