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/51031

51031

ZIP 51031 is Le Mars, Iowa, mostly in Plymouth County; area code 712; Central time.

Type
Standard
Time zone
America/Chicago
County
Plymouth +1 more
Metro area
Le Mars, IA
Population
12,808
Coordinates
42.8032, -96.1864
☼ Live from 51031 — Le Mars, IA

Weather right now

Asking the National Weather Service…

NEXRAD radar
Finding the nearest radar…
Local time: —

Where 51031 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 51031
  • 🔢 Type 51031 into a pocket calculator and turn it upside down: IEOIS — not quite a word, sorry.
  • ➕ 51031 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 10, a total 513 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 1100011101010111
  • 🏠 Its numerical neighbours: 51030 (Lawton, IA, 21 mi away) and 51033 (Linn Grove, IA, 48 mi away).
  • 🔄 Backwards, 51031 becomes 13015, which is not a ZIP code at all.
  • 👥 26 other ZIP codes are made of exactly the same digits (01351, 01531, 10153, 11053, 11530, 13051, …). The farthest-flung twin is 01531 in New Braintree, MA, 1,220 miles away.
  • 🧭 Farther north than 81% of all ZIP codes, and farther west than 72%.
  • 🎯240 miles northeast of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 51031 and you would come out at 42.80°S, 83.81°E — 791 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 20m of daylight. Shortest: 9h 01m.
  • 📏 At 234.1 square miles of land, 51031 is bigger than 93% of ZIP codes — room for about 178 Central Parks.
🌙 The sky over 51031 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population12,808This ZIP12,808
Households5,217This ZIP5,217
Housing units5,461This ZIP5,461
Median age39.0This ZIP39.0Iowa38.6US 38.9
Median household income$76,525This ZIP$76,525Iowa$75,059US $80,734
Median home value$222,800This ZIP$222,800Iowa$208,000US $332,700
Median gross rent$928This ZIP$928Iowa$972US $1,413
Bachelor's degree or higher21.9%This ZIP21.9%
Mean commute16.8 minThis ZIP16.8 min
Population density54.7 / sq miThis ZIP54.7 / sq mi

Business and tax activity

Business establishments383This ZIP383
Employees8,591This ZIP8,591
Annual payroll$629,571,000This ZIP$629,571,000
Tax returns filed6,220This ZIP6,220
Total adjusted gross income$574,574,000This ZIP$574,574,000

Land area

Land area234.14 sq miThis ZIP234.14 sq mi
Water area0.01 sq miThis ZIP0.01 sq mi

Counties 51031 spans

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

CountyShare of this ZIP
Plymouth County 98.9%
Sioux County 1.1%

Other place names in 51031

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

ZIP codes near 51031

ZIPCityDistance
51008 Brunsville, IA 4.1 mi
51045 Oyens, IA 6.6 mi
51038 Merrill, IA 9.6 mi
51036 Maurice, IA 11.5 mi
51050 Remsen, IA 12.1 mi
51024 Hinton, IA 12.8 mi
51027 Ireton, IA 13.3 mi
51041 Orange City, IA 16.3 mi
51003 Alton, IA 16.4 mi
51028 Kingsley, IA 17.5 mi

Find every ZIP code within 10 miles of 51031 →

Questions about this ZIP code

Where is ZIP code 51031?

51031 is in Le Mars, Iowa, in Plymouth County, part of the Le Mars, IA micropolitan area. Its published point location is 42.8032, -96.1864.

What county is 51031 in?

51031 spans 2 counties: Plymouth County and Sioux County. Most of it falls in Plymouth 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 51031?

Le Mars uses area code 712, from NANPA's telephone records.

What time zone is 51031 in?

51031 uses America/Chicago.

How many people live in 51031?

About 12,808 people live in ZIP code 51031, in 5,217 households, at 54.7 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 51031?

$76,525 a year, against $75,059 across Iowa.

What ZIP codes are near 51031?

The closest are 51008 (4.1 mi), 51045 (6.6 mi), 51038 (9.6 mi), 51036 (11.5 mi) and 51050 (12.1 mi).

Is 51031 a PO Box ZIP code?

51031 is a standard ZIP code. A normal ZIP code with street delivery.

Download or cite

Cite this page

zipcodes.pro. “51031 ZIP Code — Le Mars, Iowa (Plymouth County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/51031

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/51031.json

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