53033 FipsDecoder
34041 County FIPS Code

Warren County

New Jersey · County seat: Belvidere · Active county or equivalent

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FIPS code 34041 is Warren County, New Jersey. With a population of 109,739 (2022 ACS estimate), it ranks #19 in New Jersey and #556 nationally. Warren County is part of the Allentown-Bethlehem-Easton, PA-NJ. The state FIPS code for New Jersey is 34. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.

County FIPS

34041

State FIPS

34

NJ

Population

109,739

2022 ACS · #556 nationally

Density

307.5/mi²

people per sq mile

Land Area

357

sq miles

Urban/Rural

Metro — 250K–1M population

RUCC 2

How This FIPS Code Works

34 041
34 = State FIPS (New Jersey)
041 = County FIPS

The 5-digit FIPS code 34041 is formed by combining the 2-digit state identifier 34 (New Jersey) with the 3-digit county identifier 041. Together they uniquely identify Warren County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 34041

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 34041.

Median Household Income

$92,620

ACS B19013_001E

Poverty Rate

7.7%

ACS B17001 (below poverty level)

Median Age

44.0

ACS B01002_001E

Metropolitan Area

Adjacent Counties (6)

Counties that share a border with Warren County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 34041.

Federal Datasets Using Code 34041

FIPS code 34041 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 34041 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 34041
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:041",
    "in":   "state:34",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Warren County, New Jersey, income, pop, ...]
SQL — filtering by county FIPS 34041
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '34041';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '34'
  AND county_fips = '041';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 34041 is WRONG for this county
R — tidycensus 34041
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "34",
  county    = "041",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 34 (not 34) and 041 (not 41) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

ZIP Codes in Warren 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 Warren County. Why FIPS ≠ ZIP →

ZIP Code % in county
07820 100.0%
07831 100.0%
07832 100.0%
07833 100.0%
07838 100.0%
07844 100.0%
07846 100.0%
07863 100.0%
07880 100.0%
08865 100.0%
08886 100.0%
07823 100.0%
07825 97.8%
07882 95.1%
07840 76.4%
07865 64.6%
08802 42.2%
08804 39.8%
07821 16.6%
08827 9.7%
07860 6.1%
07874 2.8%

Other Counties in New Jersey