What city is ZIP code 91023?

91023 is a Mount Wilson, California ZIP code.

What county is 91023 in?

ZIP code 91023 is in Los Angeles County, California.

What time zone is ZIP code 91023 in?

91023 is in the Pacific Time zone (America/Los_Angeles).

What area code is 91023?

Phone numbers in ZIP code 91023 use area codes 747 and 818.

Can I use 91023 for a street address?

No. 91023 is only for PO Boxes. Street addresses in Mount Wilson use another ZIP code.

What ZIP codes are near 91023?

The nearest ZIP codes to 91023 are 91024 (Sierra Madre, 4.3 miles), 91003 (Altadena, 4.5 miles), 91025 (Sierra Madre, 4.5 miles) and 91001 (Altadena, 4.8 miles).

ZIP code 91023

Where is ZIP code 91023?

Mount Wilson, California

Los Angeles County · PO Box only ZIP code

ZIP code 91023 belongs to Mount Wilson, California in Los Angeles County. 91023 is a PO Box only ZIP code: it is used for post office boxes at the Mount Wilson post office, not for street addresses. It is in the Pacific Time zone and uses area codes 747 and 818. The closest ZIP codes are 91024 (Sierra Madre, 4.3 mi south), 91003 (Altadena, 4.5 mi southwest) and 91025 (Sierra Madre, 4.5 mi south).

ZIP code	91023
Type	PO Box only (no street delivery)
Status	Active
City	Mount Wilson
State	California (CA)
County	Los Angeles County
Time zone	Pacific Time · now
Area codes	747, 818
Coordinates	34.2264, -118.0662 map
3-digit prefix	910

The Census Bureau doesn’t publish population figures for po box only ZIP codes because nobody lives at a PO Box or a single organization’s address. For figures about the area, see the nearby standard ZIP codes below.

ZIP codes near 91023

ZIP code	City	Distance	Type
91024	Sierra Madre, CA	4.3 mi S	Standard
91003	Altadena, CA	4.5 mi SW	PO Box only
91025	Sierra Madre, CA	4.5 mi S	PO Box only
91001	Altadena, CA	4.8 mi SW	Standard
91104	Pasadena, CA	5.3 mi SW	Standard
91107	Pasadena, CA	5.4 mi S	Standard
91066	Arcadia, CA	6.2 mi S	PO Box only
91077	Arcadia, CA	6.2 mi S	PO Box only
91103	Pasadena, CA	6.5 mi SW	Standard
91017	Monrovia, CA	6.6 mi SE	PO Box only
91106	Pasadena, CA	6.7 mi SW	Standard
91016	Monrovia, CA	6.8 mi SE	Standard

Straight-line distance between ZIP code center points. Find every ZIP code within 10 miles of 91023 or measure the distance to another ZIP code.

How to address mail to 91023

JANE SMITH
PO BOX 123
MOUNT WILSON CA 91023

Put the city, the two-letter state code and the ZIP code on the last line. Adding the 4-digit ZIP+4 code (91023-XXXX) helps mail sort faster but isn’t required.

Questions

What city is ZIP code 91023?: 91023 is a Mount Wilson, California ZIP code.
What county is 91023 in?: ZIP code 91023 is in Los Angeles County, California.
What time zone is ZIP code 91023 in?: 91023 is in the Pacific Time zone (America/Los_Angeles).
What area code is 91023?: Phone numbers in ZIP code 91023 use area codes 747 and 818.
Can I use 91023 for a street address?: No. 91023 is only for PO Boxes. Street addresses in Mount Wilson use another ZIP code.
What ZIP codes are near 91023?: The nearest ZIP codes to 91023 are 91024 (Sierra Madre, 4.3 miles), 91003 (Altadena, 4.5 miles), 91025 (Sierra Madre, 4.5 miles) and 91001 (Altadena, 4.8 miles).