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/80309

80309

ZIP 80309 is in Boulder, Colorado, in Boulder County; area codes 720, 303 and 983; Mountain time. Boulder has 11 ZIP codes in all.

Type
No street area
Time zone
America/Denver
County
Boulder
Metro area
Boulder, CO
Coordinates
40.0150, -105.2705

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 80302, whose figures describe that area — not this ZIP code.

☼ Live from 80309 — Boulder, CO

Weather right now

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Where 80309 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 80309
  • 🔢 Type 80309 into a pocket calculator and turn it upside down: GOEOB — not quite a word, sorry.
  • ➕ 80309 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 20, a total 2,586 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 10011100110110101
  • 🏠 Its numerical neighbours: 80308 (Boulder, CO, 6 mi away) and 80310 (Boulder, CO, 1 mi away).
  • 🔄 Backwards, 80309 becomes 90308 — and that is a real ZIP code: Inglewood, CA, 833 miles away.
  • 👥 23 other ZIP codes are made of exactly the same digits (00938, 00983, 03809, 03890, 03908, 08039, …). The farthest-flung twin is 09803 in APO AE, a military post office, 7,616 miles away.
  • 🧭 Farther north than 57% of all ZIP codes, and farther west than 83%.
  • 🎯355 miles west of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 80309 and you would come out at 40.02°S, 74.73°E — 682 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 01m of daylight. Shortest: 9h 19m.
🌙 The sky over 80309 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

Business and tax activity

Business establishments21This ZIP21
Employees391This ZIP391
Annual payroll$11,462,000This ZIP$11,462,000

Land area

ZIP codes near 80309

ZIPCityDistance
80310 Boulder, CO 0.9 mi
80304 Boulder, CO 2.3 mi
80305 Boulder, CO 2.9 mi
80302 Boulder, CO 4.2 mi
80301 Boulder, CO 4.2 mi
80303 Boulder, CO 4.3 mi
80308 Boulder, CO 6.2 mi
80025 Eldorado Springs, CO 6.4 mi
80027 Louisville, CO 7.4 mi
80307 Boulder, CO 7.4 mi

Find every ZIP code within 10 miles of 80309 →

Questions about this ZIP code

Where is ZIP code 80309?

80309 is in Boulder, Colorado, in Boulder County, part of the Boulder, CO metropolitan area. Its published point location is 40.0150, -105.2705.

What county is 80309 in?

80309 lies in Boulder County.

What area code is 80309?

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

What time zone is 80309 in?

80309 uses America/Denver.

What ZIP codes are near 80309?

The closest are 80310 (0.9 mi), 80304 (2.3 mi), 80305 (2.9 mi), 80302 (4.2 mi) and 80301 (4.2 mi).

Is 80309 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. “80309 ZIP Code — Boulder, Colorado (Boulder County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/80309

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