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/51566

51566

ZIP 51566 is in Red Oak, Iowa, mostly in Montgomery County; area code 712; Central time. Red Oak has 2 ZIP codes; the other is 51591.

Type
Standard
Time zone
America/Chicago
County
Montgomery +2 more
Metro area
none
Population
7,010
Coordinates
41.0151, -95.2297
☼ Live from 51566 — Red Oak, IA

Weather right now

Asking the National Weather Service…

NEXRAD radar
Finding the nearest radar…
Local time: —

Where 51566 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 51566
  • 🔢 Type 51566 into a pocket calculator and turn it upside down: ggSIS — not quite a word, sorry.
  • ➕ As a number, 51,566 = 2 × 19 × 23 × 59. Its digits add up to 23, a total 2,533 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 1100100101101110
  • 🏠 Its numerical neighbours: 51565 (Portsmouth, IA, 46 mi away) and 51570 (Shelby, IA, 37 mi away).
  • 🔄 Backwards, 51566 becomes 66515 — and that is a real ZIP code: Morrill, KS, 79 miles away.
  • 👥 15 other ZIP codes are made of exactly the same digits (15656, 15665, 16565, 16655, 51656, 55616, …). The farthest-flung twin is 16655 in Imler, PA, 878 miles away.
  • 🧭 Farther north than 67% of all ZIP codes, and farther west than 69%.
  • 🎯194 miles northeast of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 51566 and you would come out at 41.02°S, 84.77°E — 910 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 08m of daylight. Shortest: 9h 13m.
  • 📏 At 176.4 square miles of land, 51566 is bigger than 89% of ZIP codes — room for about 134 Central Parks.
🌙 The sky over 51566 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population7,010This ZIP7,010
Households3,128This ZIP3,128
Housing units3,432This ZIP3,432
Median age42.1This ZIP42.1Iowa38.6US 38.9
Median household income$56,637This ZIP$56,637Iowa$75,059US $80,734
Median home value$134,200This ZIP$134,200Iowa$208,000US $332,700
Median gross rent$829This ZIP$829Iowa$972US $1,413
Bachelor's degree or higher20.9%This ZIP20.9%
Mean commute20.4 minThis ZIP20.4 min
Population density39.7 / sq miThis ZIP39.7 / sq mi

Business and tax activity

Business establishments207This ZIP207
Employees2,900This ZIP2,900
Annual payroll$138,717,000This ZIP$138,717,000
Tax returns filed3,070This ZIP3,070
Total adjusted gross income$201,494,000This ZIP$201,494,000

Land area

Land area176.41 sq miThis ZIP176.41 sq mi
Water area0.57 sq miThis ZIP0.57 sq mi

Counties 51566 spans

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

CountyShare of this ZIP
Montgomery County 91.4%
Page County 6.6%
Pottawattamie County 2.0%

Other place names in 51566

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

ZIP codes near 51566

ZIPCityDistance
51591 Red Oak, IA 4.0 mi
51573 Stanton, IA 7.5 mi
51533 Emerson, IA 7.9 mi
51532 Elliott, IA 10.6 mi
51638 Essex, IA 12.4 mi
51541 Henderson, IA 12.9 mi
50864 Villisca, IA 13.5 mi
51645 Imogene, IA 13.6 mi
51540 Hastings, IA 14.0 mi
50847 Grant, IA 15.5 mi

Find every ZIP code within 10 miles of 51566 →

Questions about this ZIP code

Where is ZIP code 51566?

51566 is in Red Oak, Iowa, in Montgomery County. Its published point location is 41.0151, -95.2297.

What county is 51566 in?

51566 spans 3 counties: Montgomery County, Page County and Pottawattamie County. Most of it falls in Montgomery 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 51566?

Red Oak uses area code 712, from NANPA's telephone records.

What time zone is 51566 in?

51566 uses America/Chicago.

How many people live in 51566?

About 7,010 people live in ZIP code 51566, in 3,128 households, at 39.7 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 51566?

$56,637 a year, against $75,059 across Iowa.

What ZIP codes are near 51566?

The closest are 51591 (4 mi), 51573 (7.5 mi), 51533 (7.9 mi), 51532 (10.6 mi) and 51638 (12.4 mi).

Is 51566 a PO Box ZIP code?

51566 is a standard ZIP code. A normal ZIP code with street delivery.

Download or cite

Cite this page

zipcodes.pro. “51566 ZIP Code — Red Oak, Iowa (Montgomery County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/51566

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/51566.json

Underlying data is public domain or openly licensed — sources, vintages and licences.