Legend
Official state-record hailstones (NCEI SCEC) (10)
Hawaii record, 4.25 in, Kailua, Oahu (NWS Honolulu; off view, zoom out) (1)
Former state records, since superseded (3)
DisasterAWARE archive: storms with 5 in+ stones since 2017 (17)
SPC hail reports on record-stone days before Oct 2019 (159)
NWS severe thunderstorm warnings (SV.W) near the record stones, 14 record days 2003–2026 (112) — off at load
NWS tornado warnings (TO.W) in force over a record stone (6) — off at load
Hail reports on the five MESH-era record days, 2021–2026 (228) — off at load
Where the Kankakee record stone was laser-scanned: NIU, DeKalb (1) — off at load
Dark red: official state records (NCEI State Climate Extremes Committee; Hawaii per NWS Honolulu). Hawaii's record stone (Kailua, Oahu) lies off the default view to the southwest: zoom out to see it. Gold: former records. Blue: largest real-time reports in the DisasterAWARE archive (one dot per storm). Grey: SPC reports on older record days. Orange shading: MRMS MESH radar estimate (MODELED, not measured stones), 24 h to 12 UTC. Off at load (tick them in Layers): NWS warning polygons (ALERT, IEM, all 14 record days 2003–2026), hail reports on the five MESH-era record days, NEXRAD reflectivity at Vivian, Hondo, Vigo Park and Kankakee, and the NIU lab where the Kankakee stone was scanned. Click any dot. As of 2026-10-09.
Radar-estimated hail size (MRMS MESH, MODELED)
0.75–1"
1–1.5"
1.5–2"
2–2.5"
2.5–3"
3"+
MRMS MESH_Max_1440min, 24 h to 12 UTC next day, 1 km grid. A radar estimate of maximum expected hail size, not a measured stone.
NEXRAD reflectivity, Vivian SD, 2010-07-23 23:05 UTC [6:05 PM CDT Jul 23] (N0R) (OBSERVED radar)
20–30
30–40
40–50
50–55
55–60
60–65
65+ dBZ
IEM national NEXRAD base-reflectivity composite (N0R), the 5-minute frame at or just before the stone's report time; 50 dBZ at the stone, 60 dBZ max in the box. 60+ dBZ cores often mean large hail, but reflectivity is not a stone size. Frames exist for 1995 on; shown for the four stones the article discusses most.
NEXRAD reflectivity, Hondo TX, 2021-04-29 00:35 UTC [7:35 PM CDT Apr 28] (N0Q) (OBSERVED radar)
20–30
30–40
40–50
50–55
55–60
60–65
65+ dBZ
IEM national NEXRAD base-reflectivity composite (N0Q), the 5-minute frame at or just before the stone's report time; 67.5 dBZ at the stone, 71.5 dBZ max in the box. 60+ dBZ cores often mean large hail, but reflectivity is not a stone size. Frames exist for 1995 on; shown for the four stones the article discusses most.
NEXRAD reflectivity, Vigo Park TX, 2024-06-03 00:35 UTC [7:35 PM CDT Jun 2] (N0Q) (OBSERVED radar)
20–30
30–40
40–50
50–55
55–60
60–65
65+ dBZ
IEM national NEXRAD base-reflectivity composite (N0Q), the 5-minute frame at or just before the stone's report time; 53 dBZ at the stone, 69.5 dBZ max in the box. 60+ dBZ cores often mean large hail, but reflectivity is not a stone size. Frames exist for 1995 on; shown for the four stones the article discusses most.
NEXRAD reflectivity, Kankakee IL, 2026-03-10 23:25 UTC [6:25 PM CDT Mar 10] (N0Q) (OBSERVED radar)
20–30
30–40
40–50
50–55
55–60
60–65
65+ dBZ
IEM national NEXRAD base-reflectivity composite (N0Q), the 5-minute frame at or just before the stone's report time; 66 dBZ at the stone, 73 dBZ max in the box. 60+ dBZ cores often mean large hail, but reflectivity is not a stone size. Frames exist for 1995 on; shown for the four stones the article discusses most.
