How to look up hail history for an address

Start with the NCEI Storm Events Database

This is the official, final record of severe weather, and the SPC points anyone asking about hail at a place over many years to it. To search it:³

• Open Search by Map and type the address, city or ZIP code; the tool selects the county the place falls in.¹⁰
• Choose Hail as the event type; hail can also be filtered by size.¹⁰
• Enter start and end dates as MM/DD/YYYY, or turn on Search All Years to match the same dates in every year.¹⁰
• Create a PDF report from the results; NCEI certifies a report on request at ncei.orders@noaa.gov. Bulk data comes as CSV files.¹¹

Each hail record gives the begin and end time, hail size in inches, an estimated property damage amount, who reported it and an NWS narrative.⁵

Hail is filed by county. Each point is placed by distance and compass direction from the center of a nearby town, airport or lake, with latitude and longitude rounded to hundredths of a degree, so a record near the property is not a reading at the property.^4,5

Events take 3 months to appear; for a recent storm, contact the local NWS office.^4,3

Older records are thinner. A 2022 study found only about the last two decades of hail data reliable, with data before 1990 rarely used, and Storm Data mostly leaves out hail smaller than 0.75 inch; smaller sizes appear only occasionally, when they came with severe wind or a tornado.¹²

Check SPC storm reports for a recent date

For a single date, the SPC Storm Reports page lists preliminary reports back to June 1, 1999, entered as YYMMDD. Each day runs from 1200 UTC to 1159 UTC the next day, times are in UTC, and hail sizes are in hundredths of an inch (75 means 0.75 inch).^2,13,3

A report is missing if no Local Storm Report was sent or if it arrived more than 10 days after the storm.³

Radar hail estimates (MESH)

Radar fills the gaps between reports. The Multi-Radar Multi-Sensor (MRMS) system combines data from many radars with other observations and has run at the National Centers for Environmental Prediction since 2014.⁹

Its Maximum Estimated Size of Hail (MESH) product estimates the largest hail size from radar echoes above the freezing level, on a grid of about 1 km updated every 2 minutes.^8,14

Added up over periods such as 1 hour or 1 day, MESH can help verify hail after the fact. Read it with its biases in mind:¹⁵

• MESH was designed to run high: 75% of observed hail sizes fall below the radar estimate.¹⁴
• It tends to underestimate hail in strongly tilted storms, left-moving supercells and storms with low-density, dry hailstones.⁸
• From 2012 to 2019, MESH severe hail hours a year could be 2 to 4 times those from Storm Data reports, even in the more populated parts of the Plains, and more where few people live.¹⁴
• In parts of the Southeast, MESH shows somewhat more severe hail than reports, likely because hail aloft melts in low levels before it lands.¹⁴

The NCEI Severe Weather Data Inventory, with records from 1995 to the present, holds NEXRAD radar hail signatures and exports them as CSV, KMZ or shapefile. Much of its radar-derived data shows probable conditions, not confirmed events.^6,7

What a lookup can and can't show

• Reports are more numerous in and around population centers and road networks.¹²
• In sparsely populated areas, hail may go unreported, and a report may not be the largest stone that fell.¹⁴
• Reported sizes cluster at the sizes of common reference objects, so true sizes can be larger or smaller.^14,12
• No Severe Weather Data Inventory record for a place and time does not mean severe weather did not occur.⁶
• Damage amounts in Storm Data are estimates.⁵

Commercial hail maps

Private weather companies build hail maps on the federal data and add their own data and services. The NWS keeps lists, made up of providers that sent in their details, of private alert services and of forensic meteorology services for hail claims.¹⁶

Hail alerts for a specific address

For future storms, the NWS does not send email or text alerts to the public; it lists commercial alert services that deliver by email, text, phone call and app.^16,3

Local NWS offices issue tornado, severe thunderstorm and flash flood warnings for a polygon set by latitude and longitude, not whole counties.^3,17

Wireless Emergency Alerts are free and need no sign-up, but a Severe Thunderstorm Warning sets one off only when it carries the destructive tag: hail 2.75 inches (baseball size) or larger, or 80 mph winds. Base warnings (hail 1 inch or larger) and considerable warnings (hail 1.75 inches or larger) do not.^18,19

NOAA Weather Radio receivers with SAME alert only for the counties programmed in, using a 6-digit code for each county.²⁰

How often it hails in a city: the Dallas example

For any city, the same NCEI search by county, with Hail selected and a long date range, lists the recorded hail events with a results summary. SPC climatology maps give the wider picture: the estimated daily probability of a hail report in each 80 km (50 mile) grid box, built from reports from 1982 to 2011.^10,21

For Dallas, within 124 nautical miles (about 143 miles) of the Dallas Fort Worth radar, 1980 to 2006, the SPC counted an average of 398 hail reports on 49 days a year. April and May averaged 106 and 105 hail reports, against 5 to 14 in each month from July through February.²²