21031
ZIP 21031 is in Hunt Valley, Maryland, in Baltimore County; area codes 410, 443 and 667; Eastern time. Hunt Valley has 2 ZIP codes; the other is 21065.
- Type
- Standard
- Time zone
- America/New_York
- County
- Baltimore
- Metro area
- Baltimore-Columbia-Towson, MD
- Population
- 26
- Coordinates
- 39.4874, -76.6579
Weather right now
Asking the National Weather Service…
Where 21031 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.
- 🔢 Type 21031 into a pocket calculator and turn it upside down: IEOIZ — not quite a word, sorry.
- ➕ 21031 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 7, a total 150 other ZIP codes share.
- 💾In binary, the way a computer stores it:
101001000100111 - 🏠 Its numerical neighbours: 21030 (Cockeysville, MD, 3 mi away) and 21032 (Crownsville, MD, 32 mi away).
- 🔄 Backwards, 21031 becomes 13012, which is not a ZIP code at all.
- 👥 31 other ZIP codes are made of exactly the same digits (02113, 02131, 10123, 10132, 10213, 10312, …). The farthest-flung twin is 32110 in Bunnell, FL, 743 miles away.
- 🧭 Farther north than 52% of all ZIP codes, and farther east than 83%.
- 🎯1,163 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 21031 and you would come out at 39.49°S, 103.34°E — 873 miles from Perth, Australia, the nearest big city to that spot.
- ☀Longest day of the year: 14h 58m of daylight. Shortest: 9h 23m.
- 📏 At 0.935 square miles of land, 21031 is bigger than 8% of ZIP codes — about 453 football fields.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 26This ZIP26 |
|---|---|
| Households | 19This ZIP19 |
| Housing units | 19This ZIP19 |
| Bachelor's degree or higher | 0.0% |
| Population density | 27.8 / sq miThis ZIP27.8 / sq mi |
Business and tax activity
| Business establishments | 320This ZIP320 |
|---|---|
| Employees | 16,462This ZIP16,462 |
| Annual payroll | $1,492,986,000This ZIP$1,492,986,000 |
Land area
| Land area | 0.94 sq miThis ZIP0.94 sq mi |
|---|---|
| Water area | 0.00 sq mi |
Other place names in 21031
Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.
ZIP codes near 21031
| ZIP | City | Distance |
|---|---|---|
21065 | Hunt Valley, MD | 0.2 mi |
21030 | Cockeysville, MD | 2.9 mi |
21093 | Lutherville Timonium, MD | 3.5 mi |
21131 | Phoenix, MD | 3.9 mi |
21094 | Lutherville Timonium, MD | 4.8 mi |
21152 | Sparks Glencoe, MD | 4.9 mi |
21023 | Butler, MD | 5.0 mi |
21153 | Stevenson, MD | 5.3 mi |
21139 | Riderwood, MD | 5.4 mi |
21204 | Towson, MD | 5.8 mi |
Find every ZIP code within 10 miles of 21031 →
Questions about this ZIP code
Where is ZIP code 21031?
21031 is in Hunt Valley, Maryland, in Baltimore County, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.4874, -76.6579.
What county is 21031 in?
21031 lies in Baltimore County.
What area code is 21031?
Hunt Valley uses area codes 410, 443 and 667, from NANPA's telephone records.
What time zone is 21031 in?
21031 uses America/New_York.
How many people live in 21031?
About 26 people live in ZIP code 21031, in 19 households, at 27.8 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.
What ZIP codes are near 21031?
The closest are 21065 (0.2 mi), 21030 (2.9 mi), 21093 (3.5 mi), 21131 (3.9 mi) and 21094 (4.8 mi).
Is 21031 a PO Box ZIP code?
21031 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “21031 ZIP Code — Hunt Valley, Maryland (Baltimore County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21031
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/21031.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.