San Juan County
Washington · County seat: Friday Harbor · Active county or equivalent
FIPS code 53055 is San Juan County, Washington. With a population of 18,001 (2022 ACS estimate), it ranks #32 in Washington and #1973 nationally. The state FIPS code for Washington is 53. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
53055
Population
18,001
2022 ACS · #1973 nationally
Density
103.5/mi²
people per sq mile
Land Area
174
sq miles
Urban/Rural
Nonmetro — completely rural
RUCC 9
How This FIPS Code Works
The 5-digit FIPS code 53055 is formed by combining the 2-digit state identifier 53 (Washington) with the 3-digit county identifier 055. Together they uniquely identify San Juan County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 53055
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 53055.
Median Household Income
$76,745
ACS B19013_001E
Poverty Rate
11.0%
ACS B17001 (below poverty level)
Median Age
56.5
ACS B01002_001E
Adjacent Counties (5)
Counties that share a border with San Juan County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 53055.
Federal Datasets Using Code 53055
FIPS code 53055 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 53055 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:055",
"in": "state:53",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [San Juan County, Washington, income, pop, ...]
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '53055';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '53'
AND county_fips = '055';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 53055 is WRONG for this county
library(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "53",
county = "055",
year = 2022
)
ZIP Codes in San Juan 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 San Juan County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 98297 | 100.0% |
| 98222 | 100.0% |
| 98243 | 100.0% |
| 98245 | 100.0% |
| 98250 | 100.0% |
| 98261 | 100.0% |
| 98279 | 100.0% |
| 98280 | 100.0% |
| 98286 | 100.0% |
| 98221 | 7.6% |