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/80503

80503

ZIP 80503 is in Longmont, Colorado, mostly in Boulder County; area codes 720, 303 and 983; Mountain time. Longmont has 4 ZIP codes; the others are 80501, 80502 and 80504.

Type
Standard
Time zone
America/Denver
County
Boulder +1 more
Metro area
Boulder, CO
Population
35,846
Coordinates
40.1690, -105.2104
☼ Live from 80503 — Longmont, CO

Weather right now

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Local time: —

Where 80503 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.

★ Weird and wonderful facts about 80503
  • 🔢 Type 80503 into a pocket calculator and turn it upside down: EOSOB — not quite a word, sorry.
  • ➕ As a number, 80,503 = 19 × 19 × 223. Its digits add up to 16, a total 1,922 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 10011101001110111
  • 🏠 Its numerical neighbours: 80502 (Longmont, CO, 6 mi away) and 80504 (Longmont, CO, 10 mi away).
  • 🔄 Backwards, 80503 becomes 30508, which is not a ZIP code at all.
  • 👥 27 other ZIP codes are made of exactly the same digits (03580, 03850, 05038, 05083, 05830, 08035, …). The farthest-flung twin is 03850 in Melvin Village, NH, 1,747 miles away.
  • 🧭 Farther north than 58% of all ZIP codes, and farther west than 83%.
  • 🎯352 miles west of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 80503 and you would come out at 40.17°S, 74.79°E — 672 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 02m of daylight. Shortest: 9h 18m.
  • 📏 At 91.7 square miles of land, 80503 is bigger than 76% of ZIP codes — room for about 70 Central Parks.
🌙 The sky over 80503 today
  • Working out the sun…
🌋 Shake report
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Source: USGS.

People and housing

Population35,846This ZIP35,846
Households15,153This ZIP15,153
Housing units15,737This ZIP15,737
Median age44.8This ZIP44.8Colorado37.7US 38.9
Median household income$113,620This ZIP$113,620Colorado$95,470US $80,734
Median home value$755,500This ZIP$755,500Colorado$539,400US $332,700
Median gross rent$1,872This ZIP$1,872Colorado$1,761US $1,413
Bachelor's degree or higher59.9%This ZIP59.9%
Mean commute23.1 minThis ZIP23.1 min
Population density390.7 / sq miThis ZIP390.7 / sq mi

Business and tax activity

Business establishments767This ZIP767
Employees7,488This ZIP7,488
Annual payroll$662,524,000This ZIP$662,524,000
Tax returns filed17,690This ZIP17,690
Total adjusted gross income$2,606,445,000This ZIP$2,606,445,000

Land area

Land area91.75 sq miThis ZIP91.75 sq mi
Water area3.01 sq miThis ZIP3.01 sq mi

Counties 80503 spans

A ZIP code is a mail route and ignores county lines. Shares are by overlapping land area.

CountyShare of this ZIP
Boulder County 97.9%
Larimer County 2.1%

Other place names in 80503

Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.

ZIP codes near 80503

ZIPCityDistance
80533 Hygiene, CO 1.5 mi
80544 Niwot, CO 5.0 mi
80502 Longmont, CO 5.7 mi
80501 Longmont, CO 5.7 mi
80301 Boulder, CO 8.5 mi
80304 Boulder, CO 9.5 mi
80504 Longmont, CO 9.6 mi
80513 Berthoud, CO 10.2 mi
80307 Boulder, CO 10.3 mi
80314 Boulder, CO 10.3 mi

Find every ZIP code within 10 miles of 80503 →

Questions about this ZIP code

Where is ZIP code 80503?

80503 is in Longmont, Colorado, in Boulder County, part of the Boulder, CO metropolitan area. Its published point location is 40.1690, -105.2104.

What county is 80503 in?

80503 spans 2 counties: Boulder County and Larimer County. Most of it falls in Boulder County, measured by overlapping land area — the county holding the most land in a ZIP code is not always the one holding the most residents.

What area code is 80503?

Longmont uses area codes 720, 303 and 983, from NANPA's telephone records.

What time zone is 80503 in?

80503 uses America/Denver.

How many people live in 80503?

About 35,846 people live in ZIP code 80503, in 15,153 households, at 390.7 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 80503?

$113,620 a year, against $95,470 across Colorado.

What ZIP codes are near 80503?

The closest are 80533 (1.5 mi), 80544 (5 mi), 80502 (5.7 mi), 80501 (5.7 mi) and 80301 (8.5 mi).

Is 80503 a PO Box ZIP code?

80503 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “80503 ZIP Code — Longmont, Colorado (Boulder County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/80503

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