How the data page is built
Method and sources
Housing age and tenure
US Census Bureau, American Community Survey 2020-2024 5-year estimates, by ZIP Code Tabulation Area, from api.census.gov. Fields: B25001_001 (housing units), B25034_001 and B25034_011 (all units, and units built 1939 or earlier, which gives the "built before 1940" share), B25034_002 to _004 (built 2000 or later), B25035_001 (median year built; the Census reports any median of 1939 or earlier at its floor, which we show as "before 1940"), B25003_001 and _003 (occupied, renter occupied). ZCTAs with fewer than 300 housing units are dropped. City ZIP codes are the 17 mostly inside Buffalo city limits (14222, 14213, 14201, 14203, 14208, 14209, 14211, 14207, 14216, 14214, 14212, 14210, 14206, 14220, 14215, 14202, 14204); the rest count as suburban. Shares across several ZIPs are weighted by housing units.
Flood insurance claims
OpenFEMA FIMA NFIP Redacted Claims (v3), filtered to countyCode 36029 (Erie County). Fields: yearOfLoss, reportedZipCode, ratedFloodZone, netBuildingPaymentAmount, netContentsPaymentAmount. A claim counts toward a ZIP by its reported ZIP. "1979 + 1985" counts claims with a year of loss in either year; they are the two years with the most claims in the county, by a wide margin. These are flood policy claims only.
Mold licenses
New York State Department of Labor, published on data.ny.gov as "Mold Contractor Licenses: Four Year Window" (dataset ikqx-ispy), refreshed daily. Fields: license_type (SH125 assessment, SH126 remediation), license_status, zip_code, business_name. We count rows with status Active by the first five digits of the business ZIP. "Hold both" matches business names after stripping punctuation and suffixes like LLC and Inc, so it can miss a company that files under two names. We publish counts only, never names. Individual licenses (dataset h6jr-vxqt) are counted statewide by type: 1,804 active mold assessor, 1,920 supervisor and 2,068 abatement worker licenses.
Thaw days
Daily precipitation (pcpn), snowfall (snow), snow depth (snwd) and high temperature (maxt) at Buffalo Niagara International Airport (GHCN USW00014733), via NOAA's Applied Climate Information System, 1940 through October 28, 2026. A thaw day is a day with a high of 34°F or more and either at least 0.1 inch of precipitation falling on 1 inch or more of snow cover (rain on snow), or a drop in snow depth of 3 inches or more from the day before with a high of 35°F or more (fast melt). The definition is ours, picked to catch the days that put meltwater against foundations; no agency publishes this count. A trace counts as zero. Years with more than ten missing precipitation days are left out of averages, and snowfall averages use the same years.
Humidity
NOAA NCEI Global Summary of the Day for the same airport (72528014733), daily mean dew point, 1973 on. We count days with a mean dew point of 60°F or more. Averages use 2016-2024 and 1991-2020; a year needs 340 days of data to count.
Lake Erie
NOAA CO-OPS station 9063020 (Buffalo, Lake Erie), monthly mean water level in feet above IGLD 1985, 1970 on. The record is the highest single monthly mean. The average is the mean of all months from 1991 to 2020: 571.86 feet.
Disaster declarations
OpenFEMA Disaster Declarations Summaries (v2) for New York, county code 029, filtered to floods, storms, snow, ice and wind.
Limits
Housing age describes a ZIP, not a house; plenty of 1915 houses have dry basements and plenty of 1995 ones don't. ACS figures are survey estimates with margins of error, wider in small ZIPs. One airport doesn't describe every street, and lake-effect snow can bury Orchard Park while Amherst sees flurries. License counts reflect where a company keeps its office, not where it works. Nothing here is an inspection of any property.
Refresh
A weekly job (pipeline/refresh.sh) re-pulls every source and rebuilds the site only when the derived data's hash changes. The date at the top of the data page moves only when that happens.
Cite this
Reuse is welcome under CC BY 4.0 with a link to the data page.