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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/03820

03820

ZIP 03820 is in Dover, New Hampshire, in Strafford County; area code 603; Eastern time. Dover has 3 ZIP codes; the others are 03821 and 03822.

Type
Standard
Time zone
America/New_York
County
Strafford
Population
33,440
Coordinates
43.1864, -70.8836
☼ Live from 03820 — Dover, NH

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Local time: —

Where 03820 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 03820
  • 🔢 Type 03820 into a pocket calculator and turn it upside down: OZBEO — not quite a word, sorry.
  • ➕ As a number, 3,820 = 2 × 2 × 5 × 191. Its digits add up to 13, a total 1,179 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 111011101100
  • 🏠 Its numerical neighbours: 03819 (Danville, NH, 21 mi away) and 03821 (Dover, NH, 1 mi away).
  • 🔄 Backwards, 03820 becomes 02830 — and that is a real ZIP code: Harrisville, RI, 92 miles away.
  • 👥 28 other ZIP codes are made of exactly the same digits (00823, 02038, 02830, 03082, 03280, 03802, …). The farthest-flung twin is 83002 in Jackson, WY, 1,985 miles away.
  • 🧭 Farther north than 84% of all ZIP codes, and farther east than 96%.
  • 🎯1,445 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 03820 and you would come out at 43.19°S, 109.12°E — 859 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 23m of daylight. Shortest: 8h 59m.
  • 📏 At 27.3 square miles of land, 03820 is bigger than 44% of ZIP codes — room for about 21 Central Parks.
🌙 The sky over 03820 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population33,440This ZIP33,440
Households15,062This ZIP15,062
Housing units15,453This ZIP15,453
Median age36.9This ZIP36.9New Hampshire43.3US 38.9
Median household income$94,897This ZIP$94,897New Hampshire$99,031US $80,734
Median home value$436,100This ZIP$436,100New Hampshire$402,500US $332,700
Median gross rent$1,607This ZIP$1,607New Hampshire$1,491US $1,413
Bachelor's degree or higher52.0%This ZIP52.0%
Mean commute22.8 minThis ZIP22.8 min
Population density1,225.7 / sq miThis ZIP1,225.7 / sq mi

Business and tax activity

Business establishments902This ZIP902
Employees16,911This ZIP16,911
Annual payroll$1,053,613,000This ZIP$1,053,613,000
Tax returns filed17,640This ZIP17,640
Total adjusted gross income$1,737,982,000This ZIP$1,737,982,000

Land area

Land area27.28 sq miThis ZIP27.28 sq mi
Water area2.32 sq miThis ZIP2.32 sq mi

Other place names in 03820

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

ZIP codes near 03820

ZIPCityDistance
03821 Dover, NH 0.9 mi
03822 Dover, NH 0.9 mi
03823 Madbury, NH 3.0 mi
03869 Rollinsford, NH 3.1 mi
03878 Somersworth, NH 4.6 mi
03824 Durham, NH 5.1 mi
03903 Eliot, ME 6.2 mi
03908 South Berwick, ME 7.3 mi
03839 Rochester, NH 7.7 mi
03861 Lee, NH 7.8 mi

Find every ZIP code within 10 miles of 03820 →

Questions about this ZIP code

Where is ZIP code 03820?

03820 is in Dover, New Hampshire, in Strafford County, part of the Boston-Cambridge-Newton, MA-NH metropolitan area. Its published point location is 43.1864, -70.8836.

What county is 03820 in?

03820 lies in Strafford County.

What area code is 03820?

Dover uses area code 603, from NANPA's telephone records.

What time zone is 03820 in?

03820 uses America/New_York.

How many people live in 03820?

About 33,440 people live in ZIP code 03820, in 15,062 households, at 1,225.7 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 03820?

$94,897 a year, against $99,031 across New Hampshire.

What ZIP codes are near 03820?

The closest are 03821 (0.9 mi), 03822 (0.9 mi), 03823 (3 mi), 03869 (3.1 mi) and 03878 (4.6 mi).

Is 03820 a PO Box ZIP code?

03820 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “03820 ZIP Code — Dover, New Hampshire (Strafford County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/03820

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