Northumberland County
Virginia · County seat: Heathsville · Active county or equivalent
FIPS code 51133 is Northumberland County, Virginia. With a population of 12,007 (2022 ACS estimate), it ranks #108 in Virginia and #2346 nationally. The state FIPS code for Virginia is 51. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
51133
Population
12,007
2022 ACS · #2346 nationally
Density
62.8/mi²
people per sq mile
Land Area
191
sq miles
Urban/Rural
Nonmetro — completely rural
RUCC 9
How This FIPS Code Works
The 5-digit FIPS code 51133 is formed by combining the 2-digit state identifier 51 (Virginia) with the 3-digit county identifier 133. Together they uniquely identify Northumberland County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 51133
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 51133.
Median Household Income
$64,655
ACS B19013_001E
Poverty Rate
14.8%
ACS B17001 (below poverty level)
Median Age
59.0
ACS B01002_001E
Adjacent Counties (6)
Counties that share a border with Northumberland County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 51133.
Federal Datasets Using Code 51133
FIPS code 51133 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 51133 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:133",
"in": "state:51",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Northumberland County, Virginia, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '51133';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '51'
AND county_fips = '133';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 51133 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "51",
county = "133",
year = 2022
)ZIP Codes in Northumberland 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 Northumberland County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 22511 | 100.0% |
| 22432 | 100.0% |
| 22539 | 100.0% |
| 22473 | 96.7% |
| 22435 | 93.1% |
| 22482 | 63.6% |
| 22503 | 2.0% |