Data and method
Every number on this site is computed from public NOAA and National Weather Service hail reports. Here is where they come from and how they are used.
Sources
- NOAA NCEI Storm Events Database: every event of type “Hail” filed against a county, 1955 to July 31, 2026 (424,989 reports). NOAA has no hail records before 1955.
- NWS Local Storm Reports (the reports NOAA's Storm Prediction Center compiles into its daily storm reports), via the Iowa Environmental Mesonet at Iowa State University, for days after NOAA's final data ends (1,360 reports, to November 3, 2026). These are preliminary.
- US Census Bureau 2025 Gazetteer for county and place locations, and cartographic boundaries (via us-atlas) for the maps.
How reports are matched to places
A report belongs to a city or town when it falls inside the place or within about 5 km (3 miles) of its edge (place size is approximated from its Census land area). Reports without coordinates (some older records) count for their state and county only.
Which places get a page
A county gets a page at 5 reports and a city or town at 10. Places with fewer reports are listed on their county page instead. Pages are offered to search engines only when the record has at least 10 separate hail days, including 5 in the last 20 years, so each listed page says something real about recent risk (6,700 of 8,712 city pages and 2,924 of 3,084 county pages).
Comparisons
"Median Oklahoma town on this site" means the middle value across all city pages in that state; "median county" likewise for counties. Rates use the 20 full years 2006–2025, so the partial current year does not drag them down.
Limits
This is reported hail. Rural areas and nights produce fewer reports, reporting grew a lot after the 1990s, and damage figures are as filed (not inflation-adjusted). Times are local standard time for NOAA records and UTC for preliminary reports.