Population & age
- Total population
- 558
- Median age
- 37.4
North Walpole, NH (03609)
Cheshire County · Population 558
Fresh.Data current as of Apr 24, 2026
North Walpole, NH (ZIP 03609) sits in Cheshire County. The page draws on 2 federal data feeds retrieved Apr 27. Top health signal: Health Insurance comes in below the national average at 7.3%. NCES lists 1 schools serving the area, 1 non-charter. IRS data shows average household income (AGI) of $62,275, well above the ~$45K national average per return. BLS LAUS reports county unemployment of just 2.5% (2024), well below the ~4.0% US average and consistent with a tight local labor market. Social vulnerability is low in this ZIP at the 23th percentile (CDC SVI), reflecting strong baseline resilience to public-health emergencies and natural disasters. FEMA has issued 33 federal disaster declarations affecting this ZIP since 1973 — a high-frequency exposure profile. Only 5.9% of residents under 65 are uninsured (County Health Rankings, 2025) — well below the national county median. New Hampshire has no state income tax, saving the local median household (AGI $62,275) approximately $2,865/year vs the US average effective state tax rate. New residents arriving here predominantly come from Hillsborough County, NH (IRS SOI Migration, 2022-2023). Healthcare access is the area's quieter strength; school options sit on the lighter side, so families may find themselves looking at districts a few ZIPs over. Notable: median household income $79,318, fair market rent of $1,620 for a two-bedroom, and a typical home value of $282,410, up 6.7% over the past year. Every figure on this page links to its underlying federal dataset with a retrieval date so you can audit the freshness yourself.
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Demographics
Race & ethnicity
- White
- 91.0%
- Black
- 0.0%
- Asian
- 0.0%
- Hispanic / Latino
- 0.0%
- Other / multi-racial
- 9.0%
Income & housing
- Median household income
- $79,318
- Median home value
- $173,500
Education
- Bachelor's degree or higher (age 25+)
- 31.9%
Employment
- Unemployment rate
- 2.6%
Housing
- Owner-occupied
- 158(66.9%)
- Renter-occupied
- 78(33.1%)
- Vacant units
- 58
- Built (median)
- 1938
Commute
- Public transit
- 0(0.0%)
- Work from home
- 52(17.1%)
- Avg commute
- 18.6 min
Economic wellbeing
- Below poverty line
- 72(12.9%)
- Uninsured
- 0(0.0%)
Digital access
- Broadband access
- 198(83.9%)
- No broadband
- 38(16.1%)
Language & nativity
- Foreign-born
- 20(3.6%)
- Non-English at home
- 0(0.0%)
Fair Market Rent
Fresh.HUD SAFMR · May 1, 2026Studio
$1,120
/month
1 Bed
$1,230
/month
2 Bed
$1,620
/month
3 Bed
$2,120
/month
4 Bed
$2,140
/month
HUD Fair Market Rents represent the 40th percentile of standard-quality rental housing in this area. FY2026 data.
Home values
Typical home value
$282,410
Zillow Home Value Index (ZHVI) · as of March 2026
Year-over-year change
+6.7%
vs. March 2025
5-year change
+75.7%
vs. March 2021
Metro area
Keene, NH
Metropolitan statistical area
Source: Zillow Research, ZHVI All Homes (SFR, Condo/Co-op) Time Series (zillow.com/research/data). Zillow Home Value Index (ZHVI) is copyrighted by Zillow, Inc.
New housing construction
New housing units permitted
172
Across 161 permitted buildings. Total construction value: $51.2M.
Single-family
156
91% of total units
Multifamily (2+ unit)
16
9% of total units
Single-family value
$49.6M
construction value
Multifamily value
$1.6M
construction value
Based on county-level data (2024).
Source: U.S. Census Bureau Building Permits Survey (census.gov/construction/bps). Public domain. BPS reports annual residential building permits from local permit-issuing jurisdictions, aggregated to county. A permit reflects intent to build, not a completed unit — actual construction lags by 6-24 months for multifamily projects.
Income & tax statistics
Tax returns filed
400
Average AGI
$62,275
Avg property tax
—
EITC participation
12.5%
Income distribution
- $1 – $25,00022.5% · 90
- $25,000 – $50,00030.0% · 120
- $50,000 – $75,00022.5% · 90
- $75,000 – $100,00010.0% · 40
- $100,000 – $200,00015.0% · 60
- $200,000 or more0.0% · 0
Avg mortgage interest
—
Avg charitable contribution
—
Avg capital gains
$70
Avg total income tax
—
Source: IRS Statistics of Income — Individual Income Tax Statistics by ZIP Code (irs.gov). Public domain. Dollar columns reported in thousands by the IRS; figures here display real dollars. Total ZCTA AGI for the area was $24.9M across all reported brackets.
Business & employment
Business establishments
17
Total employment
262
Annual payroll
$13.7M
Average annual pay
$52,298
Source: U.S. Census Bureau, ZIP Business Patterns (census.gov). Public domain. ZBP covers establishments with paid employees; Census suppresses employment and payroll values when fewer employers operate in a ZIP than would protect their confidentiality.
Employment & wages
Average annual pay
$59,392
Average weekly wage
$1,142
Total employment
31,134
Total establishments
2,280
That is roughly 9% below the US national average of $65,470 per worker.
Source: U.S. Bureau of Labor Statistics, Quarterly Census of Employment and Wages (bls.gov/cew). Public domain. QCEW is derived from state unemployment-insurance filings and covers ~95% of US jobs. Figures are county-level totals assigned to ZIPs whose primary county matches; small-employer cells are suppressed by BLS to protect employer confidentiality.
Unemployment
Unemployment rate
2.5%
That is 1.5 percentage points below the US national unemployment rate of about 4.0%.
Labor force
40,203
Employed
39,182
Unemployed
1,021
Based on Cheshire County, NH data (2024).
Source: U.S. Bureau of Labor Statistics, Local Area Unemployment Statistics (bls.gov/lau). Public domain. LAUS publishes monthly and annual labor-force estimates for every US county. Figures are county-level totals assigned to ZIPs whose primary county matches.
Public libraries
Public-library outlets
1
Single library outlet
One public-library outlet serves this ZIP — typical of suburban and small-town areas. Card holders also have full access to the rest of the system's branches.
Buildings
1
1 branch
Avg hours / week
12.7
across outlets in this ZIP
Avg square feet
600
per outlet
Outlets in this ZIP
- 1.North Walpole Branch Library
Public libraries provide free WiFi, computer access, children's programming, job-seeking resources, and meeting space — community infrastructure beyond books. FY2023 outlet inventory from the federal Public Libraries Survey.
Source: Institute of Museum and Library Services (imls.gov). Per-ZIP counts of active public-library outlets — central buildings, branches, and bookmobiles — operated by federally reporting library systems.
Federal Disaster Declarations
Federally Declared Disasters
33
Date Range
1973–2023
Most Recent Declaration
SEVERE STORMS AND FLOODING
Flood — declared September 14, 2023 (DR-4740)
Incident period: July 9, 2023 – July 17, 2023
Top Incident Types
- Severe Storm10 (30%)
- Flood8 (24%)
- Snowstorm7 (21%)
- Hurricane4 (12%)
- Biological2 (6%)
- Other2 (6%)
Individual Assistance
5
Direct help to disaster survivors
Households Program
2
Housing & temporary lodging support
Public Assistance
33
Repair of public facilities & roads
Hazard Mitigation
13
Funding to reduce future disaster risk
FEMA declares disasters at the county level; counts here include every federally declared disaster touching any county that overlaps this ZIP. Statewide declarations and pre-1964 records without county granularity are excluded. Program flags reflect which FEMA assistance categories were activated (Individual Assistance, Households, Public Assistance, Hazard Mitigation). Source: fema.gov/openfema. Public domain.
Climate
30-year averages (1991-2020) from the nearest GHCN-D weather station. Temperature and precipitation values reflect typical annual conditions, not any single year.
Avg. temperature
45.4°F
33.4° – 57.3°
Annual precipitation
46.1"
Annual snowfall
59.8"
Heating · cooling days
7,500.9 · 375.1
Annual base 65°F
Nearest station: KEENE, NH US, 15.4 miles from the centroid of North Walpole, NH (ZIP 03609)
Source: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (ncei.noaa.gov). Public domain.
Air quality
Median daily AQI
36
GoodGood 302dModerate 64d
Peak AQI (2024)
93
Moderate
Primary pollutant
Ozone
223 days as main pollutant
Days measured
366
Based on Cheshire County data (2024).
Source: U.S. Environmental Protection Agency, Air Quality System (epa.gov). Public domain. Only counties with EPA AQS monitoring stations appear here (~30% of US counties); rural ZIPs whose primary county has no monitor will not show this section.
Community health profile
Years of potential life lost (per 100K)
7,142
That is roughly 1,058 years per 100,000 below the national county median (~8,200).
Premature death is the headline composite outcome CHR reports — age-adjusted, all-cause, before age 75.
Fair or poor health
15%
of adults self-report
Poor physical health days
3.9
avg per adult per month
Poor mental health days
5.5
avg per adult per month
Uninsured
5.9%
of residents under 65
Primary care MDs
67
per 100,000 residents
Preventable hospital stays
1,895
per 100K Medicare enrollees
Food environment (0-10)
8.7
10 = best access & security
Exercise access
68%
residents near a facility
Flu vaccinated
52%
of Medicare enrollees
Low birth weight (under 2,500 g) accounts for 6.0% of live births in this county — an early-life health input that downstream outcomes track against.
Based on Cheshire data (2025 CHR release).
Source: County Health Rankings & Roadmaps, University of Wisconsin Population Health Institute (countyhealthrankings.org). Annual release. Underlying source datasets vary by measure (CDC BRFSS, NCHS Vital Statistics, AHA, USDA Food Environment Atlas, and others). Figures are county-level and assigned to every ZIP whose primary county matches.
Food access
Food access status
Moderate food access challenges
19.3% of Cheshire County, NH residents live more than 1 mile (urban) or 10 miles (rural) from the nearest supermarket.
Grocery stores
0.16
per 1,000 residents
Supercenters & clubs
0.05
per 1,000 residents
SNAP-authorized stores
0.80
accepting food benefits
Fast-food restaurants
0.59
per 1,000 residents
Among low-income residents, 4.2% are low-access — those without a supermarket within 1 mile (urban) or 10 miles (rural).
Per-1,000 figures show how many of each store type exist in Cheshire County, NH for every 1,000 residents. Higher grocery and supercenter density usually means easier access to fresh food; higher convenience-store-only density (with low grocery rate) often signals a food swamp.
Source: USDA Economic Research Service, Food Environment Atlas (ers.usda.gov). County-level metrics fanned to ZIP via the primary county in the Census ZCTA-county relationship file. Variable years differ per family (stores ~2020, low-access ~2019).
Safety
FBI publishes crime data at the county level. Numbers below cover the primary county that contains this ZIP. Rates are per 100,000 residents in the area covered by reporting agencies.
Violent crime rate
—
per 100K residents · 1 reports
Property crime rate
—
per 100K residents · 6 reports
Homicide
0
Robbery
0
Burglary
0
Vehicle theft
0
County-level data for Cheshire (2024)
Source: U.S. Federal Bureau of Investigation, Uniform Crime Reporting Program (cde.ucr.cjis.gov). Public domain. Coverage varies by reporting agency; areas with partial agency coverage may understate true crime totals.
Who’s moving in and out
Net migration (2022-2023)
▲+439 people
+214 households • +$42.5M net AGI flow
Moved in
2,977households
4,643 people • $236.5M AGI
Moved out
2,763households
4,204 people • $194.0M AGI
Where new residents came from
- Hillsborough County, NH — 330 households
- Worcester County, MA — 149 households
- Windham County, VT — 140 households
- Middlesex County, MA — 106 households
- Sullivan County, NH — 67 households
Where departing residents went
- Hillsborough County, NH — 255 households
- Windham County, VT — 110 households
- Middlesex County, MA — 79 households
- Worcester County, MA — 73 households
- Sullivan County, NH — 70 households
Incoming households reported an average AGI of $79,447 versus departing households' $70,218.
Source: U.S. Internal Revenue Service, Statistics of Income, Migration Data (irs.gov). Public domain. Migration is measured by year-over-year changes in the address on individual tax returns; figures are county-level totals attributed to ZIPs whose primary county matches. Foreign migration contributes to inflow/outflow totals but does not appear in the top-county lists. Small flows are suppressed by IRS to protect taxpayer confidentiality.
Taxes & benefits in New Hampshire
State-level rules that apply to every resident of ZIP 03609. Numbers reflect the most recent published year per source.
Tax rates
Income tax
None
No state income tax
Sales tax (combined)
0.00%
State 0.00% · avg local 0.00%
Property tax (effective)
2.38%
Median $5,616/year
Tax burden rank
15 of 50
9.20% of personal income
For ZIP 03609: A household at this ZIP's median AGI of $62,275 keeps approximately $2,865 more annually than residents of the typical income-tax state. Applied to this ZIP's typical home value of $282,410, that works out to roughly $6,712/year in property tax.
Paid family leave
Program
Voluntary (private insurance framework)
Voluntary (private insurance framework)
Replacement: 60% AWW, max $2128
Safety net
SNAP eligibility
200% FPL
Broad-Based Categorical Eligibility (raises gross income limit above federal 130% floor). No asset test.
Sources: Tax Foundation (state tax rates & brackets), Bipartisan Policy Center (paid family leave), USDA FNS (SNAP categorical eligibility).
Other ZIPs near 03609
Nearby ZIPs by distance
05101 (Bellows Falls, 2.3 mi) · 05158 (Westminster, 2.8 mi) · 03604 (3 mi) · 05154 (Saxtons River, 4.2 mi) · 03602 (5 mi) · 03608 (Walpole, 5.3 mi)
Compare ZIP-level stats — population, schools, housing, climate — across nearby areas. Source: U.S. Census Bureau ZCTA basemap.
Data sources used on this page
SourcesFresh.CDC PLACES · Apr 24, 2026Fresh.NCES CCD via Urban Institute EDP · Apr 27, 2026Fresh.HUD SAFMR · May 1, 2026
All data on this page is sourced from federal government datasets · Not AI-generated · Methodology
Health profile
Crude prevalence estimates from CDC PLACES, derived from BRFSS small-area modeling. Population-level figures only.
Obesity
30.8%
2.2pp below the 33.0% national rate.
High Blood Pressure
31.9%
Tracks close to the 32.0% national rate.
Depression
24.9%
2.9pp above the 22.0% national rate.
Annual Checkup
73.6%
2.4pp below the 76.0% national rate.
Health Insurance
7.3%
5.7pp below the 13.0% national rate.
Diabetes
9.1%
Tracks close to the 11.0% national rate.
Schools in this ZIP
1 school serves this ZIP, including 1 non-charter.
| School | Type | Grades | Enrollment |
|---|---|---|---|
| North Walpole School | Public | 2–4 | 82 |
Schools listed from NCES Common Core of Data via the Urban Institute Education Data Portal.
Fresh.NCES CCD via Urban Institute EDP · Apr 27, 2026What these numbers say together
North Walpole, NH (ZIP 03609) sits in Cheshire County. The page draws on 2 federal data feeds retrieved Apr 27. Top health signal: Health Insurance comes in below the national average at 7.3%. NCES lists 1 schools serving the area, 1 non-charter. IRS data shows average household income (AGI) of $62,275, well above the ~$45K national average per return. BLS LAUS reports county unemployment of just 2.5% (2024), well below the ~4.0% US average and consistent with a tight local labor market. Social vulnerability is low in this ZIP at the 23th percentile (CDC SVI), reflecting strong baseline resilience to public-health emergencies and natural disasters. FEMA has issued 33 federal disaster declarations affecting this ZIP since 1973 — a high-frequency exposure profile. Only 5.9% of residents under 65 are uninsured (County Health Rankings, 2025) — well below the national county median. New Hampshire has no state income tax, saving the local median household (AGI $62,275) approximately $2,865/year vs the US average effective state tax rate. New residents arriving here predominantly come from Hillsborough County, NH (IRS SOI Migration, 2022-2023). Healthcare access is the area's quieter strength; school options sit on the lighter side, so families may find themselves looking at districts a few ZIPs over. Notable: median household income $79,318, fair market rent of $1,620 for a two-bedroom, and a typical home value of $282,410, up 6.7% over the past year. Every figure on this page links to its underlying federal dataset with a retrieval date so you can audit the freshness yourself.
The two domains pull in different directions. Healthcare access reads strong, but the on-paper school count is on the lighter side — that’s less a quality signal and more a density one. Households here often look at districts a few ZIPs over for school choice while keeping their providers local.
One concrete reading worth keeping: Depression prevalence sits higher the national rate at 24.9%. Each figure on this page links to the original federal dataset with its retrieval date — this synthesis is a reading, not a substitute for the underlying records.
Frequently Asked Questions — ZIP 03609
What is the obesity rate in ZIP 03609?
30.8%, which is 2.2 percentage points below the national average of 33.0% (CDC PLACES, retrieved Apr 24, 2026).
What is the depression rate in ZIP 03609?
24.9%, which is 2.9 percentage points above the national average of 22.0% (CDC PLACES, retrieved Apr 24, 2026).
What is the high blood pressure rate in ZIP 03609?
31.9%, which is 0.1 percentage points below the national average of 32.0% (CDC PLACES, retrieved Apr 24, 2026).
How many schools are in ZIP 03609?
1 school serves this ZIP, including 1 public school (NCES CCD, retrieved Apr 27, 2026). No charter schools are listed in this ZIP by NCES CCD.
Does ZIP 03609 have charter schools?
No charter schools are listed in ZIP 03609 by NCES CCD (retrieved Apr 27, 2026).
Are there high schools in ZIP 03609?
No high schools are listed in this ZIP by NCES CCD (retrieved Apr 27, 2026).
What is the population of ZIP 03609?
558 people live in ZIP 03609, with a median age of 37.4 (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
What is the median household income in ZIP 03609?
$79,318 per year (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
Is ZIP 03609 mostly renters or homeowners?
In ZIP 03609, 66.9% of occupied housing units are owner-occupied and 33.1% are renter-occupied (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
How do people commute in ZIP 03609?
In ZIP 03609, 17.1% of workers work from home. Public transit is used by 0.0% of commuters (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
What is the poverty rate in ZIP 03609?
12.9% of the population in ZIP 03609 lives below the federal poverty line (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
What percentage of households in ZIP 03609 have broadband internet?
83.9% of households in ZIP 03609 have broadband internet access (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
What is the typical home value in ZIP 03609?
The typical home value in ZIP 03609 is $282,410, up 6.7% from a year ago (Zillow Home Value Index, retrieved May 1, 2026).
Are home values rising or falling in ZIP 03609?
Home values are up 6.7% over the past year and up 75.7% over the past five years (Zillow Home Value Index, retrieved May 1, 2026).
What is the average household income in ZIP 03609?
The average Adjusted Gross Income reported on tax returns from ZIP 03609 (North Walpole, NH) is $62,275 per return (IRS SOI Tax Year 2022, retrieved May 2, 2026).
How much do homeowners pay in property tax in ZIP 03609?
Tax returns from ZIP 03609 report an average of $0 per return in real-estate tax deductions (IRS SOI Tax Year 2022, retrieved May 2, 2026).
What percentage of residents in ZIP 03609 earn over $200,000?
0.0% of tax returns from ZIP 03609 (North Walpole, NH) report Adjusted Gross Income of $200,000 or more (IRS SOI Tax Year 2022, retrieved May 2, 2026).
How many businesses are in ZIP 03609?
As of 2022, 17 business establishments operated in ZIP 03609 employing 262 workers (Census ZIP Business Patterns, retrieved May 3, 2026).
What is the average salary in ZIP 03609?
The average annual pay across all local establishments in ZIP 03609 is $52,298, based on Census ZIP Business Patterns 2022 data (retrieved May 3, 2026).
How vulnerable is ZIP 03609 to disasters and public health emergencies?
According to the CDC Social Vulnerability Index (2022), ZIP 03609 ranks in the 23th percentile nationally for social vulnerability — a low vulnerability profile (retrieved May 3, 2026).
What is the biggest vulnerability factor in ZIP 03609?
Housing Type & Transportation is the highest-scoring CDC SVI theme for ZIP 03609, ranking in the 40th percentile nationally (CDC/ATSDR Social Vulnerability Index 2022, retrieved May 3, 2026).
How many federally declared disasters has ZIP 03609 experienced?
FEMA has recorded 33 federal disaster declarations affecting ZIP 03609 between 1973–2023 (FEMA OpenFEMA Disaster Declarations, retrieved May 3, 2026).
What kinds of disasters most often hit ZIP 03609?
Severe Storm is the most common federally declared disaster type affecting ZIP 03609, accounting for 10 of 33 declarations (30%, FEMA OpenFEMA, retrieved May 3, 2026).
What was the most recent disaster declared for ZIP 03609?
The most recent FEMA disaster declaration affecting ZIP 03609 was "SEVERE STORMS AND FLOODING" — a flood declared in 2023 (DR-4740) (FEMA OpenFEMA, retrieved May 3, 2026).
What is the climate like in ZIP 03609?
ZIP 03609 has an average annual temperature of 45.4°F and 46.1" of annual precipitation based on the KEENE, NH US weather station 15.4 miles from the ZIP centroid (NOAA 1991–2020 Climate Normals, retrieved May 8, 2026).
What taxes apply in ZIP 03609?
New Hampshire has no state income tax. For a household earning the local median AGI of $62,275, this saves approximately $2,865 per year compared to the national average effective state tax rate. The combined state and local sales tax rate is 0.00% (Tax Foundation 2025).
Does New Hampshire have paid family leave?
New Hampshire runs an active paid family leave program offering up to — weeks of paid leave per year, with a maximum weekly benefit of $2,128 (Bipartisan Policy Center 2026).
What data is available for ZIP 03609?
This page covers health outcomes from CDC PLACES (40 metrics), school information from NCES CCD (1 school), demographics from the Census ACS 5-Year (2022), home values from the Zillow Home Value Index, income & tax statistics from the IRS SOI (Tax Year 2022), local business & employment from Census ZIP Business Patterns (2022), social vulnerability scores from the CDC/ATSDR SVI (2022), federal disaster declarations from FEMA OpenFEMA (33 on record), climate normals from NOAA NCEI (1991-2020), county-level crime data from the FBI Crime Data Explorer (2024), and state-level tax rates from the Tax Foundation. Data is refreshed on Mubboo's standard schedule.
How current is this data?
Health data retrieved Apr 24, 2026 from CDC PLACES. School data retrieved Apr 27, 2026 from NCES CCD. Demographics retrieved Apr 30, 2026 from Census ACS 5-Year (2022). Home values retrieved May 1, 2026 from Zillow Research. Income & tax statistics retrieved May 2, 2026 from IRS SOI (Tax Year 2022). Business & employment retrieved May 3, 2026 from Census ZBP (2022). Social vulnerability scores retrieved May 3, 2026 from CDC/ATSDR SVI (2022). Federal disaster declarations retrieved May 3, 2026 from FEMA OpenFEMA (33 on record). Climate normals retrieved May 8, 2026 from NOAA NCEI (1991-2020). County-level crime data retrieved May 4, 2026 from the FBI Crime Data Explorer (2024). State-level tax rates retrieved 2026-05-05 15:58:22.284+00 from the Tax Foundation.
Other ZIPs near 03609
Nearby ZIPs by distance
05101 (Bellows Falls, 2.3 mi) · 05158 (Westminster, 2.8 mi) · 03604 (3 mi) · 05154 (Saxtons River, 4.2 mi) · 03602 (5 mi) · 03608 (Walpole, 5.3 mi)
Compare ZIP-level stats — population, schools, housing, climate — across nearby areas. Source: U.S. Census Bureau ZCTA basemap.
More Info topics
Have a specific question about ZIP 03609?
Ask Mubboo — launching Q4 2026.
Data refreshed via Mubboo's ETL pipeline; oldest source on this page retrieved Apr 24, 2026.
Social Vulnerability Index
Overall SVI
23rd percentile
Low Vulnerability
Based on 1 census tract, population 93
Vulnerability Themes
Persons with Disability
13
Without HS Diploma
6
Without Health Insurance
2
Adults Age 65+
20
The Social Vulnerability Index uses U.S. Census data to identify communities most at risk during public health emergencies and natural disasters. Higher percentiles indicate greater vulnerability. Tract-level scores are aggregated to this ZCTA via Census 2020 ZCTA→Tract crosswalk, weighted by land-area share. Source: atsdr.cdc.gov. Public domain.