53033 FipsDecoder
16031 County FIPS Code

Cassia County

Idaho · County seat: Burley · Active county or equivalent

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FIPS code 16031 is Cassia County, Idaho. With a population of 24,859 (2022 ACS estimate), it ranks #15 in Idaho and #1653 nationally. Cassia County is part of the Burley, ID. The state FIPS code for Idaho is 16. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.

County FIPS

16031

State FIPS

16

ID

Population

24,859

2022 ACS · #1653 nationally

Density

9.7/mi²

people per sq mile

Land Area

2,565

sq miles

Urban/Rural

Nonmetro — urban 2.5K–19.9K, adjacent to metro

RUCC 6

How This FIPS Code Works

16 031
16 = State FIPS (Idaho)
031 = County FIPS

The 5-digit FIPS code 16031 is formed by combining the 2-digit state identifier 16 (Idaho) with the 3-digit county identifier 031. Together they uniquely identify Cassia County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 16031

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 16031.

Median Household Income

$63,525

ACS B19013_001E

Poverty Rate

10.4%

ACS B17001 (below poverty level)

Median Age

33.1

ACS B01002_001E

Metropolitan Area

Adjacent Counties (8)

Counties that share a border with Cassia County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 16031.

Federal Datasets Using Code 16031

FIPS code 16031 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.

Using FIPS Code 16031 in Code

Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.

Census ACS API — Python 16031
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:031",
    "in":   "state:16",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Cassia County, Idaho, income, pop, ...]
SQL — filtering by county FIPS 16031
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '16031';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '16'
  AND county_fips = '031';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 16031 is WRONG for this county
R — tidycensus 16031
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "16",
  county    = "031",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 16 (not 16) and 031 (not 31) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

ZIP Codes in Cassia County

ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Cassia County. Why FIPS ≠ ZIP →

ZIP Code % in county
83323 100.0%
83311 100.0%
83312 100.0%
83346 100.0%
83318 99.9%
83344 68.8%
83342 65.3%
83211 35.1%
83350 6.9%

Other Counties in Idaho