Sources
Where our data comes from
Every figure on City Zip Compare is drawn from a primary U.S. government source. Below is the full list, with direct links and the schedule on which each dataset is updated.
Last updated May 2026
Currently in use
U.S. Census Bureau — American Community Survey 5-year (ACS5)
The backbone of City Zip Compare. ACS5 covers population, age, income, housing value, rent, homeownership, education, employment, commuting and more, for every ZIP code tabulation area, place, county and state in the United States. Pulled via the official Census Data API. Vintage refreshes annually in December.
U.S. Census Bureau — Decennial Census
Used for population baselines and historical comparisons. census.gov/decennial. Updates every 10 years.
Coming next
U.S. Bureau of Labor Statistics (BLS)
Monthly state and metro-area unemployment, occupational employment statistics, and area wage estimates. bls.gov/data. Updates monthly to annually depending on series.
IRS Statistics of Income — Migration Data
County-to-county and state-to-state migration flows derived from filed tax returns. Useful for understanding where households are actually moving, year over year. irs.gov/statistics. Annual.
FBI Uniform Crime Reporting (UCR / NIBRS)
Reported violent and property crime by jurisdiction. FBI Crime Data Explorer. Annual.
U.S. Department of Housing and Urban Development (HUD)
Fair Market Rents, Income Limits, and the HUD User datasets. huduser.gov/datasets. Annual.
NOAA Climate Data
30-year climate normals (temperature, precipitation, snowfall) by station. ncei.noaa.gov. Decadal updates.
How to verify
Every figure we publish can be reproduced by querying the source above for the same geography and vintage. If you spot a discrepancy, please tell us — we treat divergence from the underlying source as a bug.