91931
ZIP 91931 is Guatay, California, in San Diego County; area codes 619 and 858; Pacific time.
- Type
- Standard
- Time zone
- America/Los_Angeles
- County
- San Diego
- Metro area
- San Diego-Chula Vista-Carlsbad, CA
- Population
- 494
- Coordinates
- 32.8376, -116.5803
Weather right now
Asking the National Weather Service…
Where 91931 is
Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.
- 🔢 Type 91931 into a pocket calculator and turn it upside down: IEGIG — not quite a word, sorry.
- ➕ As a number, 91,931 = 7 × 23 × 571. Its digits add up to 23, a total 2,533 other ZIP codes share.
- 💾In binary, the way a computer stores it:
10110011100011011 - 🏠 Its numerical neighbours: 91921 (Chula Vista, CA, 32 mi away) and 91932 (Imperial Beach, CA, 36 mi away).
- 🔄 Backwards, 91931 becomes 13919, which is not a ZIP code at all.
- 👥 11 other ZIP codes are made of exactly the same digits (11939, 19139, 19193, 19319, 19931, 39119, …). The farthest-flung twin is 11939 in East Marion, NY, 2,481 miles away.
- 🧭 Farther south than 85% of all ZIP codes, and farther west than 89%.
- 🎯1,110 miles west of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 91931 and you would come out at 32.84°S, 63.42°E — 949 miles from Port Louis, Mauritius, the nearest big city to that spot.
- ☀Longest day of the year: 14h 19m of daylight. Shortest: 9h 59m.
- 📏 At 8.2 square miles of land, 91931 is bigger than 25% of ZIP codes — room for about 6.2 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 494This ZIP494 |
|---|---|
| Households | 242This ZIP242 |
| Housing units | 270This ZIP270 |
| Median age | 65.2This ZIP65.2California37.9US 38.9 |
| Median household income | $63,750This ZIP$63,750California$99,122US $80,734 |
| Bachelor's degree or higher | 22.6%This ZIP22.6% |
| Population density | 60.2 / sq miThis ZIP60.2 / sq mi |
Business and tax activity
| Business establishments | 12This ZIP12 |
|---|---|
| Employees | 59This ZIP59 |
| Annual payroll | $3,535,000This ZIP$3,535,000 |
Land area
| Land area | 8.21 sq miThis ZIP8.21 sq mi |
|---|---|
| Water area | 0.00 sq mi |
ZIP codes near 91931
| ZIP | City | Distance |
|---|---|---|
91962 | Pine Valley, CA | 3.6 mi |
91916 | Descanso, CA | 5.9 mi |
91948 | Mount Laguna, CA | 6.5 mi |
91901 | Alpine, CA | 8.7 mi |
91903 | Alpine, CA | 10.8 mi |
91963 | Potrero, CA | 13.1 mi |
91906 | Campo, CA | 13.8 mi |
91935 | Jamul, CA | 15.1 mi |
91917 | Dulzura, CA | 16.9 mi |
92021 | El Cajon, CA | 17.1 mi |
Find every ZIP code within 10 miles of 91931 →
Questions about this ZIP code
Where is ZIP code 91931?
91931 is in Guatay, California, in San Diego County, part of the San Diego-Chula Vista-Carlsbad, CA metropolitan area. Its published point location is 32.8376, -116.5803.
What county is 91931 in?
91931 lies in San Diego County.
What area code is 91931?
Guatay uses area codes 619 and 858, from NANPA's telephone records.
What time zone is 91931 in?
91931 uses America/Los_Angeles.
How many people live in 91931?
About 494 people live in ZIP code 91931, in 242 households, at 60.2 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.
What is the median household income in 91931?
$63,750 a year, against $99,122 across California.
What ZIP codes are near 91931?
The closest are 91962 (3.6 mi), 91916 (5.9 mi), 91948 (6.5 mi), 91901 (8.7 mi) and 91903 (10.8 mi).
Is 91931 a PO Box ZIP code?
91931 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “91931 ZIP Code — Guatay, California (San Diego County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/91931
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/91931.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.