National Hail Map — where it hits, year after year

Hail is most frequent across the Great Plains. The corridor running from west Texas and the Oklahoma/Kansas panhandles north through Nebraska, eastern Colorado, and into Wyoming — often called "hail alley" — sees the most large-hail days in the country. The Front Range of Colorado and the southern Plains light up year after year on this map.

"Hail alley" is the informal name for the high-frequency hail region centered on northeastern Colorado, southeastern Wyoming, and western Nebraska, where some areas average seven to nine or more hail days a year. The combination of altitude, strong updrafts, and a freezing level close to the ground produces frequent, often large hail.

Hail tracks the severe-thunderstorm season. Across most of the country the peak runs spring through mid-summer, generally April–July, with May and June the busiest in the central Plains. The southern Plains and Southeast can begin earlier in spring.

No. It shows reported hail — National Weather Service Local Storm Reports called in by spotters, law enforcement, and the public. Reporting is denser where more people and trained spotters are, so the map carries a population bias. The persistent geographic corridors, though, are physically real and line up with radar-based hail climatologies such as NSSL's MESH analyses.

Use the search box above the map: type your address, town, or ZIP (or tap the pin button to use your location) and the page pulls every National Weather Service hail report within 25 miles over the last five years — dates, reported stone sizes, and distances — with a printable report. Reports are town-level precision, so use them to confirm the day and the neighborhood; your own photos confirm the property.

Rules of thumb from insurance and agronomy experience: 1″ (quarter size) can damage asphalt shingles, siding, and tender crops; 1.5″ (ping-pong) is the common “damaging” threshold used on this page and dents vehicles and roofs reliably; 2″+ (hen egg and up) breaks windows, strips crops to stalks, and totals roofs. Damage also depends on wind, stone density, and duration — a long soft-hail event can shred a bean field that a brief hard-hail event leaves alone.

No — this page is the record, not the forecast. It shows where hail was actually reported, which is what claims, history checks, and risk decisions need. For whether conditions favor severe weather in the next few days, use the NWS Storm Prediction Center outlooks; for whether the next few days are workable on your ground, the AGSIST spray advisory reads the local forecast for you.

The US record stone fell at Vivian, South Dakota on July 23, 2010 — 8.0″ in diameter, 18.62″ in circumference, just under 2 pounds. Grapefruit-class stones (4″+) show up somewhere on the Plains most years; this map's size legend tops out at baseball+ because that's already roof-totaling, crop-stripping hail.

Mostly mid-afternoon through evening — roughly 3–9 PM local — when daytime heating peaks and thunderstorm updrafts are strongest. Overnight hail happens, especially with organized storm complexes on the Plains, but if you're planning around exposure (equipment out, cattle moves, a roofing job), the afternoon is the window that matters.

Metal resists puncture far better than asphalt shingle, but it dents — 1″ stones can cosmetically dent softer metal panels, and 2″+ can dent nearly any residential metal roof. Many policies distinguish cosmetic from functional metal-roof damage, which is exactly why a dated report from this page plus your own photos beats memory in a claim conversation.

Hail is layered ice built by thunderstorm updrafts — warm-season, can be huge. Sleet is small frozen raindrops from winter storms — never large, never from thunderstorms. Graupel ("soft hail") is snow pellets coated in rime — soft, crushable, harmless. If it's summer, it's a thunderstorm, and it bounces hard off the driveway — it's hail, and it belongs on this map.

Terminal velocity scales with size: penny hail falls around 20–25 mph, golf balls around 50 mph, baseballs near 75 mph, and softball-class stones can exceed 100 mph. That speed, more than the weight alone, is why 2″ hail breaks what 1″ hail only dents.

Hail is covered by crop-hail insurance, a named-peril product that's separate from federal Multi-Peril Crop Insurance (MPCI). Because hail risk is so geographically concentrated, growers on the high-frequency corridors often carry crop-hail to cover the gap. If your ground sits in a bright zone here, that's a conversation worth having — Farmers First Agri Service writes crop-hail in WI and MN.