ZIP code · Monrovia · Maryland · United States
ZIP code 21770 — Monrovia
ZIP code 21770 serves Monrovia, Maryland.
- Postal code
- 21770Single source Value from one source, not cross-checked.
- City
- Monrovia
- County
- Frederick FIPS 24021
- State
- Maryland
- Country
- United States
- Coordinates
- 39.3512, -77.2494 — precision precise (locality)
View on OpenStreetMap - Population
- 7,815 (ZCTA, ACS 5-year)
- Population density
- 683 / sq mi
- Land area
- 11.4 sq mi (29.7 km²) (ZCTA, ACS 5-year)
- Median household income
- $184,464
- Per-capita income
- $63,232
- Median age
- 41.2
- Households
- 2,394
- Housing units
- 2,448
- Median home value
- $599,700
- 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 21770 with another ZIP · ZIPs within 25 miles · distance from 21770
Map of ZIP code 21770
Climate — monthly normals
Warmest month Jul (avg high 84°F), coldest Jan (avg low 25°F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 39 | 43 | 52 | 64 | 73 | 80 | 84 | 83 | 76 | 65 | 53 | 44 |
| Avg low °F | 25 | 26 | 33 | 43 | 53 | 62 | 66 | 65 | 58 | 47 | 36 | 30 |
| Precip in | 3.4 | 3.0 | 4.0 | 3.6 | 4.3 | 4.7 | 4.5 | 4.2 | 4.8 | 4.0 | 3.5 | 3.9 |
NOAA 1991–2020 climate normals from the nearest station: DAMASCUS 3 SSW (6.0 mi) · NOAA NCEI
Places in ZIP 21770
- 2 schools
- 1 doctors & dentists
- 1 pharmacies
- 3 restaurants & cafés
- 6 parks
- 6 playgrounds
- 1 post offices
- 2 places of worship
- 2 banks
- 1 gas 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