ZIP code · O Fallon · Missouri · United States

ZIP code 63366 — O Fallon

ZIP code 63366 serves O Fallon, Missouri.

Postal code
63366
Single source Value from one source, not cross-checked.
City
O Fallon
County
Saint Charles FIPS 29183
State
Missouri
Country
United States
Coordinates
38.8239, -90.7427 — precision precise (locality)
View on OpenStreetMap
Population
54,449 (ZCTA, ACS 5-year)
Population density
786 / sq mi
Land area
69.3 sq mi (179.5 km²) (ZCTA, ACS 5-year)
Median household income
$98,237
Per-capita income
$43,569
Median age
39.2
Households
20,558
Housing units
21,204
Median home value
$283,900
Median gross rent
$1,274 / month
Congressional districts
MO-3 (also MO-2) (119th Congress)
USDA hardiness zone
6b (-5 to 0 °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)
Area code
636
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 88°F), coldest Jan (avg low 21°F).

JanFebMarAprMayJunJulAugSepOctNovDec
Avg high °F394556677684888781695544
Avg low °F212533435463686557453527
Precip in2.42.43.54.74.84.34.23.83.13.13.52.6

NOAA 1991–2020 climate normals from the nearest station: ST PETERS 2 SE (9.1 mi) · NOAA NCEI

Places in ZIP 63366

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