ZIP Codes of Alexander County, IL

Population & People
Population & People
Total Population
4,841
Household Income
Household Income
Median Income
$51,503
Housing
Housing
Total Housing Units
2,925
Business & Economy
Business & Economy
Total Businesses
75
Employment
Employment
Employment Rate
46.01%
Education
Education
Bachelor's Degree+
12.54%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 7 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:7 ZIP Codes (6 Standard, 1 PO Box, 0 Unique) [See All]
Area Codes:618 / 730
Timezone:Central (GMT -06:00)
Local Time:2:11:58 PM
Population:4,841 [See All]
FIPS:17003
CBSA:Cape Girardeau, MO-IL
Land Area:255 sq mi
Water Area:19 sq mi
Coordinates:37.1721, -89.3319
Quick Link:
https://www.zip-codes.com/county/il-alexander.asp
Need Alexander data in your app? Look up ZIP, county, and city data with a single API call.
Try Free
Notable population decline
Lost 38.0% of residents since 2014.
Among Illinois's 5 oldest counties
Median age 48.4.

Standout ZIPs in this County


Most Populous
Cairo · 1,765 people
36.5% of county total
Highest Income
Thebes · $64,076 median
1.2× county average
Largest Land Area
Tamms · 64.6 sq mi
Spans the most ground
Fastest Growth
Thebes · -9.8% (10-yr)
1,079 → 973 residents
Most Educated
Cairo · 13.3% bachelor's+
167 of 1,255 adults 25+

Things worth knowing about Alexander County


4,841 residents live across 7 ZIPs covering 255 sq mi, served by 7 distinct USPS-recognized cities.

Population moved from 7,804 to 4,841 from 2014 to 2024 — a -38.0% change. 0 ZIPs gained residents, 6 lost.

The county's wealthiest ZIP 62990 (Thebes, $64,076 median) and poorest ZIP 62914 (Cairo, $41,103) are 17.4 miles apart — a 1.6× income gap across local geography.

Median home values vary 4.3× across this county — from $31,900 in 62914 (Cairo) to $136,900 in 62990 (Thebes).

Density varies across the county — from 13 people/sq mi in 62957 (Mc Clure) to 73 in 62914 (Cairo).

Educational attainment ranges from 0.8% bachelor's+ in 62969 (Olive Branch) to 16.3% in 62988 (Tamms) — the breadth of educational profiles across the area.

Within Illinois, this is the #98 most populous of 102 counties and ranks #99 for median household income .

Weighted by population, the typical household earns about $50,212 across the county — reflecting what a typical resident sees, not a simple ZIP average.

12.5% of adults age 25+ hold a bachelor's degree or higher (435 of 3,470 reporting).

6 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Alexander County


Population decline

Alexander County lost 38.0% of residents between 2014 and 2024. ZIPs that shed the largest share:

Olive Branch
-47.3%
596 → 314 residents
Tamms
-42.2%
1,988 → 1,149 residents
Mc Clure
-41.0%
1,085 → 640 residents
Cairo
-40.6%
2,969 → 1,765 residents

All ZIP Codes in Alexander County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
62914CairoStandard1,765$41,10324.2-40.6%
62988TammsStandard1,149$54,77964.6-42.2%
62990ThebesStandard973$64,07646.9-9.8%
62957Mc ClureStandard640$46,05349.5-41.0%
62969Olive BranchStandard31420.7-47.3%
62962Miller CityStandard049.0-100.0%
62993UnityPO Box0.0

Adjacent & Nearby Counties