ZIP Code 91978

91978 is one of California's ZIP codes, delivering to addresses in Spring Valley, San Diego County.

City: Spring Valley
County: San Diego County
State: California
Prefix: 919xx

Where this code sits

91978 is part of the 919xx range, the group of codes handled by one mail processing centre. Spring Valley is served by 4 ZIP codes in total.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 91978 delivers to without sharing its boundary.

ZIP codes nearest 91978

The ZIP codes whose reference points sit closest to 91978.
ZIP code	Distance	Delivers to
ZIP code 91977	2.3 mi	Spring Valley, CA
ZIP code 91976	2.4 mi	Spring Valley, CA
ZIP code 91979	2.4 mi	Spring Valley, CA
ZIP code 91941	3.6 mi	La Mesa, CA
ZIP code 92019	3.9 mi	El Cajon, CA
ZIP code 92020	4.2 mi	El Cajon, CA
ZIP code 91946	4.2 mi	Lemon Grove, CA
ZIP code 91945	4.2 mi	Lemon Grove, CA

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 91978, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 91978. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.