Red Willow County
Nebraska · County seat: McCook · Active county or equivalent
FIPS code 31145 is Red Willow County, Nebraska. With a population of 10,690 (2022 ACS estimate), it ranks #23 in Nebraska and #2432 nationally. The state FIPS code for Nebraska is 31. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
31145
Population
10,690
2022 ACS · #2432 nationally
Density
14.9/mi²
people per sq mile
Land Area
717
sq miles
Urban/Rural
Nonmetro — urban 2.5K–19.9K, not adjacent to metro
RUCC 7
How This FIPS Code Works
The 5-digit FIPS code 31145 is formed by combining the 2-digit state identifier 31 (Nebraska) with the 3-digit county identifier 145. Together they uniquely identify Red Willow County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 31145
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 31145.
Median Household Income
$58,344
ACS B19013_001E
Poverty Rate
12.2%
ACS B17001 (below poverty level)
Median Age
41.5
ACS B01002_001E
Adjacent Counties (5)
Counties that share a border with Red Willow County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 31145.
Federal Datasets Using Code 31145
FIPS code 31145 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 31145 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.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:145",
"in": "state:31",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Red Willow County, Nebraska, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '31145';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '31'
AND county_fips = '145';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 31145 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "31",
county = "145",
year = 2022
)ZIP Codes in Red Willow 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 Red Willow County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 69036 | 100.0% |
| 69020 | 83.0% |
| 69034 | 78.7% |
| 69001 | 66.5% |
| 69026 | 64.3% |
| 69022 | 17.5% |
| 69046 | 11.7% |
| 69024 | 2.7% |