Alton, Illinois Hail Report and Map: May 4, 2026
Was there hail in Alton, IL on May 4, 2026? Radar estimated hail up to 1.31 inches inside the town limits of Alton on May 4, 2026 (Eastern time). Radar estimates of at least 0.5 inch covered 82% of the town. Across the report area, the maximum radar estimate was 1.85 inches. The strongest part of the swath was about 41 miles east of Alton, IL. Radar detected hail aloft in this area between about 11:05 p.m. CT on May 3, 2026 and 8:40 p.m. CT on May 4, 2026.
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Hail estimates at a glance
| Storm date (Eastern time) | May 4, 2026 (Monday) |
|---|---|
| Maximum radar estimate across the area | 1.85 inches; strongest part of the swath about 41 miles east of Alton, IL |
| Maximum radar estimate inside Alton | 1.31 inches |
| Share of Alton with radar estimates of at least 0.5 inch | 82% |
| Approximate radar timing | Between about 11:05 p.m. CT on May 3, 2026 and 8:40 p.m. CT on May 4, 2026 (Central time) |
| County coverage includes (0.5 inch or larger) | Madison County (194 sq mi), Fayette County (98 sq mi), Bond County (89 sq mi) and Clay County (44 sq mi) |
| Area with radar estimates of 0.5 inch or larger | about 424 square miles |
| Area with radar estimates of 1 inch or larger | about 80 square miles |
| Source | NOAA MRMS radar hail estimates (MESH) |
Which towns had hail on May 4, 2026?
Radar estimated hail of at least 0.5 inch inside these town limits, using U.S. Census boundaries. Each percentage is the share of town area with those estimates.
| Town | County | Maximum radar estimate inside town limits | Town area with estimates of at least 0.5 inch |
|---|---|---|---|
| Moro, IL | 1.74 inches | 100% | |
| Iola, IL | 1.64 inches | 100% | |
| Bethalto, IL | Madison County | 1.57 inches | 86% |
| Worden, IL | Madison County | 1.41 inches | 100% |
| Alton, IL | Madison County | 1.31 inches | 82% |
| Godfrey, IL | Madison County | 1.31 inches | 34% |
| Livingston, IL | Madison County | 1.12 inches | 100% |
| Williamson, IL | 1.07 inches | 64% | |
| Greenville, IL | Bond County | 1.02 inches | 86% |
| Old Ripley, IL | 0.99 inch | 100% | |
| East Alton, IL | Madison County | 0.93 inch | 57% |
| Holiday Shores, IL | Madison County | 0.91 inch | 100% |
| St. Peter, IL | 0.86 inch | 100% | |
| Rosewood Heights, IL | Madison County | 0.79 inch | 100% |
How big was the hail in Alton?
Radar estimated hail up to 1.31 inches inside the town limits of Alton. Among the listed towns, the highest estimate was 1.74 inches inside the limits of Moro. The maximum estimates in Greenville, East Alton and Rosewood Heights were 1.02 inches or less. A town's maximum isn't an estimate for every home. Check the swath for estimates around an address.
What time did radar detect hail?
Radar detected hail aloft in this area between about 11:05 p.m. CT on May 3, 2026 and 8:40 p.m. CT on May 4, 2026. We used 139 NOAA radar hail detections in this area to estimate the window. We trim outlying detection times when enough are available, then round down to five-minute marks. It doesn't give an arrival time at an address.
Data source and limits
We use NOAA's MRMS radar product MESH (Maximum Estimated Size of Hail) for hail-size estimates. Each town's figure is the maximum inside its Census town limits. The percentage is the town area with estimates of at least 0.5 inch. A town's maximum isn't an estimate for every home. Each storm date covers one calendar day in Eastern time. A late-evening storm west of the Eastern time zone can appear under two dates. Radar estimates don't confirm hail on the ground or roof damage. Hail of 0.5 to 0.75 inch can damage roofs, especially older roofs. An estimate below 1 inch doesn't rule out damage. Read how we calculate sizes and times.