ZIP code · Guasti · California · United States

ZIP code 91743 — Guasti

ZIP code 91743 serves Guasti, California.

Postal code: 91743
Single source Value from one source, not cross-checked.
City: Guasti
County: San Bernardino
State: California
Country: United States
Coordinates: 34.0650, -117.5864 — precision precise (locality)
View on OpenStreetMap
USDA hardiness zone: 10a (30 to 35 °F)
Planting / growing zone from the 2023 USDA Plant Hardiness Zone Map: average annual extreme minimum temperature, 1991–2020.
Time zone: America/Los_Angeles (UTC−8 / UTC−7 DST)
Area codes: 909, 840 (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 91743 with another ZIP · ZIPs within 25 miles · distance from 91743

Climate — monthly normals

Warmest month Aug (avg high 95°F), coldest Dec (avg low 44°F).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high °F	68	68	72	76	80	86	94	95	91	83	75	67
Avg low °F	45	46	49	51	56	60	65	65	64	57	49	44
Precip in	2.6	3.1	1.6	0.8	0.3	0.0	0.1	0.0	0.1	0.4	0.8	1.9

NOAA 1991–2020 climate normals from the nearest station: ONTARIO INTL AP (1.0 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