HOTTEST 🥵
POST OFFICE
The hottest Post Office location is in Death Valley, CA. Summer temperatures in Death Valley can reach above 120 degrees.
Fact source: Address Management
Largest ZIP Code — Continental US
Largest ZIP
in continental U.S.
The largest ZIP Code in the continental United States is 99734, Prudhoe Bay, AK, which measures 30,683 square miles.
Largest ZIP Code — Contiguous US
Largest ZIP
in contiguous U.S.
The largest ZIP Code in the contiguous United States is 89049, Tonopah, NV, at 10,821 square miles.
Introduction of the ZIP Code
Decoding
the ZIP Code
The Zoning Improvement Plan (ZIP) Code was launched in 1963 to better process and deliver increasing volumes of U.S. Mail. The first number in the five-digit ZIP Code represents a general geographic area of the nation, “0” in the east, moving to “9” in the west. The next two numbers represent regional areas, and the final two identify specific Post Offices. In 1983, the ZIP+4 Code was introduced.
Decoding the code.  In 1983, the ZIP+4 Code was introduced. The extra four numbers enable mail to be sorted to a specific street. In 1991, two more numbers were added so that mail could be sorted directly to a residence or business. Today, the use of the ZIP Code extends far beyond the mailing industry, including being a fundamental component in the nation’s 911 emergency system.
There are 41,552 ZIP Codes in the country. They range from 00501, belonging to the Internal Revenue Service in Holtsville, NY, to 99950 in Ketchikan, AK. Easiest to remember? How about 12345, a unique ZIP Code for General Electric in Schenectady, NY.
Mr. ZIP helped promote the new ZIP Code concept in 1963.
Remote Encoding Center
Write badly?
We can still read it!
The USPS Remote Encoding Center in Salt Lake City examined 841,260,847 images of poorly written addresses in fiscal year 2025.
Letter mail at a processing plant that cannot be read by the automated equipment has an image taken and transmitted to the Remote Encoding Center (REC). At the REC, employees look at the image and type in address information. The information is matched up with a valid address, the data is transmitted back to the equipment at the plant, and a barcode is printed on the letter. That barcode can be read by any letter processing machine in the Postal Service, keeping the letter within the automated stream of mail in the postal network.
Floating Post Office — Halibut Cove, AK
Floating
Post Office
This Post Office floats! The Halibut Cove Post Office in Homer, AK, (ZIP Code 99603) floats. The office is a small houseboat that is permanently tied to a dock.
Addresses added daily
6,015
addresses added daily
The Postal Service added an average of 6,015 addresses to its delivery network every day in fiscal year 2025.
Longest Main Street in America
33-mile-long
Main Street
The longest Main Street in the country is located in Island Park, ID, and is 33 miles long.
Number of Main streets
21,722
Main streets
The most common street name in the country is “Main” — there are 21,722 of them!
Number of ZIP Codes
41,554
ZIP Codes
There are 41,554 ZIP Codes in the country. They range from 00501, belonging to the Internal Revenue Service in Holtsville, NY, to 99950 in Ketchikan, AK. The easiest ZIP Code to remember? How about 12345, a unique ZIP Code for General Electric in Schenectady, NY.
Quick! What’s that ZIP Code?
The Zoning Improvement Plan (ZIP) Code was launched in 1963 to better process and deliver increasing volumes of U.S. Mail. The first number in the five-digit ZIP Code represents a general geographic area of the nation, “0” in the east, moving
to “9” in the west. The next two numbers represent regional areas, and the final two identify specific Post Offices. In 1983, the ZIP+4 Code was introduced.
Most street deliveries
157,668
deliveries from one office
The Post Office location with the most possible street deliveries is Heritage Station in San Antonio, TX (78245, 78250, 78251, 78253) — with 157,668 deliveries.
Coldest Post Office
Coldest
Post Office
Our Post Office in Utqiagvik, North Slope of Alaska — formerly Barrow (99723) — experiences the coldest temperatures of any Post Office location in the United States.
Shortest delivery route
Shortest
delivery route
The shortest delivery route is rural route 012 in Woodinville, WA (98072). On this route, the carrier travels 2.45 miles and delivers to 1,419 boxes.
Longest delivery route
longest
delivery route
The longest delivery route is rural route 001 in Sidney, MT (59270) — 195.2 miles daily, delivering to 319 boxes.
Easiest ZIP Code to remember
12345
easiest to remember
The easiest to remember ZIP Code is 12345, a unique ZIP Code for General Electric in Schenectady, NY.
Highest ZIP Code number
HIGHEST
ZIP Code
The highest numbered ZIP Code is 99950 in Ketchikan, AK.
Lowest ZIP Code number
LOWEST
ZIP Code number
The lowest ZIP Code number is 00501, unique for the Internal Revenue Service in Holtsville, NY.
Oldest Post Office (in the same building)
Oldest
Post Office
The Hinsdale, NH, Post Office (03451) has been located in the same building since 1816.
Largest retail space
LARGEST
retail space
The largest U.S. Postal Service retail space is the James A. Farley Post Office in New York, NY (10001), at 33,100 square feet.
Smallest Post Office
smallest
POST OFFICE
The smallest Post Office is located in Ochopee, FL (34141) and is 61.3 square feet. The building used to be a storage facility for irrigation pipes of an adjacent tomato farm. It was converted into a Post Office in 1953, after a fire that destroyed a previous Post Office and general store.
There is a sign beside the office that reads:
OCHOPEE POST OFFICE
Considered to be the smallest post office in the United States, this building was formerly an irrigation pipe shed belonging to the J.T. Gaunt Company tomato farm. It was hurriedly pressed into service by postmaster Sidney Brown after a disastrous night fire in 1953 burned Ochopee’s general store and post office. The present structure has been in continuous use ever since — as both a post office and ticket station for Trailway’s bus lines — and still services residents in a three-county area, including deliveries to Seminole and Miccosukee Indians living in the region. Daily business often includes requests from tourists and stamp collectors the world over for the famed Ochopee postmark. The property was acquired by the Wooten Family in 1992.
— Collier County Board of County Commissioners
Centermost Post Office — 48 states
Stuck
in the middle
The most centered Post Office within the 48 contiguous states is located in Lebanon, KS.
Centermost Post Office — 50 states
MOST CENTRAL
Post Office of them all
The centermost Post Office within all 50 states is located in Belle Fourche, SD.
Northernmost Post Office — 50 states
Northmost
Utqiagvik, AK
The northernmost Post Office location within the 50 states is in Utqiagvik, AK (formerly Barrow).
Northernmost Post Office — 48 states
NORTHERNMOST
Post Office within 48 states
The northernmost Post Office location within the 48 contiguous states is in Angle Inlet, MN.
Southernmost Post Office — 50 states
SOUTHERNMOST
within the 50 states
The southernmost Post Office location within the 50 states is located in Naalehu, HI.
Southernmost Post Office — 48 states
SOUTHERNMOST
within 48 states
The southernmost Post Office location within the 48 contiguous states is located in Key West, FL.
Easternmost Post Office — 50 states
EASTERNMOST
POST OFFICE
The easternmost Post Office location in the 50 states is in Lubec, ME.
Westernmost Post Office — 50 states
WESTERNMOST
within the 50 states
The westernmost Post Office location in the 50 states is in Gambell, AK.
Westernmost Post Office — 48 states
WESTERNMOST
in the 48 contiguous states
The westernmost Post Office location in the 48 contiguous states is in La Push, WA.
Wettest Post Office
WETTEST
U.S. Post Office
The wettest Post Office is the Kapaa Post Office in Hawaii near Mt. Waialeale. The area receives around 450 inches of rainfall per year.
Lowest Post Office
⬇️ LOWEST
U.S. Post Office
The lowest U.S. Post Office is located in Death Valley, CA (92328), at 282 feet below sea level. This is also the driest and hottest Post Office location.
Highest Post Office
⬆️ HIGHEST
U.S. Post Office
The highest Post Office in the United States is located in Alma, CO (80420), at 10,578 feet above sea level.
