ZIP code · Helen · Maryland · United States

ZIP code 20635 — Helen

ZIP code 20635 serves Helen, Maryland.

Postal code: 20635
Single source Value from one source, not cross-checked.
City: Helen
County: St. Mary's
State: Maryland
Country: United States
Coordinates: 38.3121, -76.6077 — precision precise (locality)
View on OpenStreetMap
USDA hardiness zone: 7b (5 to 10 °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, 227 (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.

Tools: compare 20635 with another ZIP · ZIPs within 25 miles · distance from 20635

Climate — monthly normals

Warmest month Jul (avg high 88°F), coldest Jan (avg low 30°F).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high °F	45	48	55	65	74	84	88	86	80	69	59	50
Avg low °F	30	31	38	47	58	68	73	71	65	53	43	35

NOAA 1991–2020 climate normals from the nearest station: SOLOMONS (8.5 mi) · NOAA NCEI

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 · NOAA NCEI · usda-phzm. Data generated on 2026-08-21. Methodology · Report an error on this page