How we work

Methodology & Data Sources

How PlainCities collects, matches and presents data for every US city — the federal sources, the join keys, and the limits of each dataset.

Methodology detail

Data Sources

PlainCities builds city profiles from four official federal government databases:

  • U.S. Census Bureau American Community Survey (ACS) 5-Year 2023 — Population, demographics, household income, home values, poverty rates, education levels, labor force participation, and median age for 28,000+ cities. Source: census.gov/acs
  • FBI Uniform Crime Report (UCR) — Violent and property crime rates for 7,000+ cities that report to the FBI's UCR program. Source: ucr.fbi.gov
  • NOAA Climate Normals (1991–2020) — Average temperature, precipitation, and snowfall for 3,500+ cities based on 30-year climate averages. Source: ncei.noaa.gov
  • NCES Common Core of Data (CCD) — Public school counts for 15,000+ cities from the National Center for Education Statistics. Source: nces.ed.gov/ccd

Coverage

PlainCities covers 28,702 U.S. cities and places as the core Census geography. Not all data dimensions are available for every city — crime data covers 7,000+ cities that report to FBI UCR; climate data covers 3,500+ cities with NOAA monitoring stations.

How We Process the Data

  1. Download raw datasets from each agency (Census ACS, FBI UCR, NOAA, NCES)
  2. Parse and normalize each dataset independently
  3. Cross-match cities across databases using FIPS codes (Census), geographic name matching (FBI, NOAA), and NCES place codes
  4. No data is modified, interpolated, or editorialized — we present exactly what each agency reports
  5. When a data point is unavailable for a city (e.g., no FBI crime reporting, no NOAA station), we display "Data not available" rather than estimating
  6. Load into our search-optimized database

Rankings Methodology

Rankings are computed from the underlying data points — not from subjective scoring systems. Crime rankings use FBI-reported rates per 100,000 population. Climate rankings use NOAA 30-year normals. All rankings compare cities within the same geographic set (e.g., cities with populations over 10,000) for fairness.

Data Currency

The Census Bureau releases new ACS 5-Year estimates annually. FBI, NOAA, and NCES update on their own schedules. We update our database when new data from each source becomes available. ACS 5-Year 2023 data is the most recent available as of our last update.

Limitations

  • Crime data covers only cities that voluntarily report to the FBI UCR — approximately 7,000 of 28,000+ cities
  • NOAA climate data covers approximately 3,500 cities with monitoring stations; other cities have no climate data
  • ACS 5-Year estimates are derived from surveys with margins of error — exact values for small cities may have wide confidence intervals
  • City boundary definitions can differ between agencies, affecting cross-source matching

How the Source Agencies Collect Data

The American Community Survey is conducted by the Census Bureau as a continuous survey of approximately 3.5 million U.S. households per year. ACS 5-Year estimates combine five years of survey data to produce reliable statistics for small geographic areas including cities, towns, and census-designated places. The survey covers demographics, income, education, housing, and employment through mailed questionnaires and follow-up interviews.

The FBI UCR program collects crime data from approximately 18,000 law enforcement agencies nationwide through voluntary reporting. Agencies submit monthly counts of offenses and arrests using standardized crime definitions. NOAA Climate Normals are computed from 30 years of weather station observations, using quality-controlled data from the Cooperative Observer Program and automated weather stations. NCES collects school data annually through mandatory surveys of all public school districts.

Data Accuracy Commitment

PlainCities presents government data without modification or interpolation. When data is missing for a city from any source, we display it as unavailable rather than estimating. Cross-source matching is performed using official geographic identifiers (FIPS codes) where possible, and geographic name matching where FIPS codes are not shared across datasets. If you find any data that appears incorrect, please contact us and we will verify against the source data.

Editorial Workflow

Content on PlainCities is compiled by our editorial team. Our pipeline uses automated tooling to join federal datasets (Census ACS, FBI UCR, NOAA Climate Normals, NCES) into readable city and neighborhood profiles, generate comparisons, and apply consistent templates across 28,000+ cities and 85,000+ census tracts. The PlainCities editorial team, operating under Kiznis Studio, reviews methodology, validates data integrity, and is responsible for corrections. Numbers on every page are derived directly from the cited source — no automated tooling is used to invent, interpolate, or estimate statistics. Narrative framing, guides, and explanatory text are drafted by our editorial team for accuracy and tone.

Contact

Questions about our methodology or found a data error? Reach us at hello@plaincities.com or through our contact page.