Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — ZIP/91017

91017

ZIP 91017 is in Monrovia, California, in Los Angeles County; area code 626; Pacific time. Monrovia has 2 ZIP codes; the other is 91016.

Type
No street area
Time zone
America/Los_Angeles
County
Los Angeles
Coordinates
34.1481, -117.9990

The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

This ZIP code has no Census tabulation area of its own. Its point falls inside ZCTA 91016, whose figures describe that area — not this ZIP code.

☼ Live from 91017 — Monrovia, CA

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Where 91017 is

This ZIP code has no Census tabulation area, so there is no boundary to draw — the marker is its published point location.

★ Weird and wonderful facts about 91017
  • 🔢 Type 91017 into a pocket calculator and turn it upside down: LIOIG — not quite a word, sorry.
  • ➕ As a number, 91,017 = 3 × 3 × 3 × 3371. Its digits add up to 18, a total 2,332 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 10110001110001001
  • 🏠 Its numerical neighbours: 91016 (Monrovia, CA, 0 mi away) and 91020 (Montrose, CA, 14 mi away).
  • 🔄 Backwards, 91017 becomes 71019 — and that is a real ZIP code: Coushatta, LA, 1,433 miles away.
  • 👥 32 other ZIP codes are made of exactly the same digits (01719, 01971, 07191, 09171, 10179, 10917, …). The farthest-flung twin is 09171 in APO AE, a military post office, 5,642 miles away.
  • 🧭 Farther south than 78% of all ZIP codes, and farther west than 91%.
  • 🎯1,138 miles west of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 91017 and you would come out at 34.15°S, 62.00°E — 1,000 miles from Saint-Denis, Reunion, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 26m of daylight. Shortest: 9h 52m.
🌙 The sky over 91017 today
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  • Checking the USGS…

Source: USGS.

Business and tax activity

Business establishments8This ZIP8
Employees35This ZIP35
Annual payroll$3,714,000This ZIP$3,714,000

Land area

ZIP codes near 91017

ZIPCityDistance
91016 Monrovia, CA 0.3 mi
91009 Duarte, CA 1.4 mi
91008 Duarte, CA 1.8 mi
91006 Arcadia, CA 1.8 mi
91066 Arcadia, CA 2.2 mi
91077 Arcadia, CA 2.2 mi
91010 Duarte, CA 2.4 mi
91007 Arcadia, CA 3.1 mi
91025 Sierra Madre, CA 3.2 mi
91024 Sierra Madre, CA 3.3 mi

Find every ZIP code within 10 miles of 91017 →

Questions about this ZIP code

Where is ZIP code 91017?

91017 is in Monrovia, California, in Los Angeles County, part of the Los Angeles-Long Beach-Anaheim, CA metropolitan area. Its published point location is 34.1481, -117.9990.

What county is 91017 in?

91017 lies in Los Angeles County.

What area code is 91017?

Monrovia uses area code 626, from NANPA's telephone records.

What time zone is 91017 in?

91017 uses America/Los_Angeles.

What ZIP codes are near 91017?

The closest are 91016 (0.3 mi), 91009 (1.4 mi), 91008 (1.8 mi), 91006 (1.8 mi) and 91066 (2.2 mi).

Is 91017 a PO Box ZIP code?

Possibly. The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

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Cite this page

zipcodes.pro. “91017 ZIP Code — Monrovia, California (Los Angeles County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/91017

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/91017.json

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