ZIP code · Keymar · Maryland · United States

ZIP code 21757 — Keymar

ZIP code 21757 serves Keymar, Maryland.

Postal code
21757
Single source Value from one source, not cross-checked.
City
Keymar
County
Carroll FIPS 24013
State
Maryland
Country
United States
Coordinates
39.5656, -77.2817 — precision precise (locality)
View on OpenStreetMap
Population
2,810 (ZCTA, ACS 5-year)
Population density
80 / sq mi
Land area
35.2 sq mi (91.1 km²) (ZCTA, ACS 5-year)
Median household income
$98,520
Per-capita income
$44,948
Median age
42.2
Households
1,068
Housing units
1,129
Median home value
$414,300
Median gross rent
$1,345 / month
Congressional districts
MD-2 (also 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)
Area codes
240, 301 (from the nearest rate centre)
Telephone area codes serving this ZIP (NANPA central-office assignments). A ZIP and an area code are different boundaries; at a border both codes may apply.

Climate — monthly normals

Warmest month Jul (avg high 85°F), coldest Jan (avg low 22°F).

JanFebMarAprMayJunJulAugSepOctNovDec
Avg high °F404352647281858477665444
Avg low °F222330405160646255443327
Precip in3.52.54.23.94.34.34.33.55.23.83.43.8

NOAA 1991–2020 climate normals from the nearest station: EMMITSBURG 2 SE (7.6 mi) · NOAA NCEI

Places in ZIP 21757

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