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/03866

03866

ZIP 03866 is in Rochester, New Hampshire, in Strafford County; area code 603; Eastern time. Rochester has 4 ZIP codes; the others are 03839, 03867 and 03868.

Type
No street area
Time zone
America/New_York
County
Strafford
Coordinates
43.3045, -70.9756

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 03867, whose figures describe that area — not this ZIP code.

☼ Live from 03866 — Rochester, NH

Weather right now

Asking the National Weather Service…

NEXRAD radar
Finding the nearest radar…
Local time: —

Where 03866 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 03866
  • 🔢 Type 03866 into a pocket calculator and turn it upside down: ggBEO — not quite a word, sorry.
  • ➕ As a number, 3,866 = 2 × 1933. Its digits add up to 23, a total 2,533 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 111100011010
  • 🏠 Its numerical neighbours: 03865 (Plaistow, NH, 32 mi away) and 03867 (Rochester, NH, 1 mi away).
  • 🔄 Backwards, 03866 becomes 66830 — and that is a real ZIP code: Admire, KS, 1,345 miles away.
  • 👥 18 other ZIP codes are made of exactly the same digits (06836, 30668, 36068, 36608, 36860, 38066, …). The farthest-flung twin is 83660 in Parma, ID, 2,271 miles away.
  • 🧭 Farther north than 84% of all ZIP codes, and farther east than 96%.
  • 🎯1,440 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 03866 and you would come out at 43.30°S, 109.02°E — 868 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 24m of daylight. Shortest: 8h 58m.
🌙 The sky over 03866 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

Business and tax activity

Business establishments4This ZIP4
Employees38This ZIP38
Annual payroll$2,844,000This ZIP$2,844,000

Land area

ZIP codes near 03866

ZIPCityDistance
03867 Rochester, NH 0.8 mi
03868 Rochester, NH 2.2 mi
03839 Rochester, NH 2.5 mi
03878 Somersworth, NH 5.6 mi
03835 Farmington, NH 6.1 mi
03901 Berwick, ME 6.7 mi
03825 Barrington, NH 6.9 mi
03815 Center Strafford, NH 7.2 mi
04027 Lebanon, ME 7.3 mi
03869 Rollinsford, NH 8.9 mi

Find every ZIP code within 10 miles of 03866 →

Questions about this ZIP code

Where is ZIP code 03866?

03866 is in Rochester, New Hampshire, in Strafford County, part of the Boston-Cambridge-Newton, MA-NH metropolitan area. Its published point location is 43.3045, -70.9756.

What county is 03866 in?

03866 lies in Strafford County.

What area code is 03866?

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

What time zone is 03866 in?

03866 uses America/New_York.

What ZIP codes are near 03866?

The closest are 03867 (0.8 mi), 03868 (2.2 mi), 03839 (2.5 mi), 03878 (5.6 mi) and 03835 (6.1 mi).

Is 03866 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.

Download or cite

Cite this page

zipcodes.pro. “03866 ZIP Code — Rochester, New Hampshire (Strafford County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/03866

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/03866.json

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