Princeton, IA Hail Storm – May 2026

A hail storm tracked through Princeton, IA on May 18, 2026, producing 1.34-inch stones and generating 64 NWS alerts across the metro area. The event included both radar-detected signatures and multiple spotter-verified reports during the overnight and daytime periods.

What Happened

A cluster of thunderstorms moved across the Princeton metro beginning before dawn and redeveloped through mid-afternoon. Dual-polarization radar detected significant hail returns at 3:47 AM CDT with an indicative size near 1.08 inches. An off-duty NWS employee reported half-dollar size hail at 3:51 AM CDT, which field crews logged as roughly 1.25 inches and tied closely to the early radar signature.

NWS warnings continued through the day. The storm stream produced a long series of NWS warning-only alerts from mid-morning into early evening, with isolated radar-detected 1.0-inch signatures appearing near late morning and late afternoon. A delayed spotter report at 9:40 AM CDT noted 1.0-inch hail, and a public report near Winfield at 11:29 AM CDT described 1.0-inch stones east of Winfield. In total, 64 NWS alerts were issued for this storm complex, reflecting sustained convective activity and repeated warning polygons across the Princeton metro.

Radar and spotter signals aligned at several times, while many alerts were issued on the basis of NWS warning polygons without additional radar-sized returns. The sequence shows an early, stronger pulse before dawn and intermittent re-intensification through the afternoon.

Damage Assessment

Field reports and radar mapping indicate concentrated surface impacts near central Princeton in the pre-dawn pulse and a second corridor of reports to the east toward Winfield late morning. The off-duty NWS employee’s 3:51 AM CDT observation corresponds with nearby radar returns and local tree limb abrasion reported on residential property assessments in central Princeton. The 11:29 AM CDT public report placed 1.0-inch hail east of Winfield; municipal crews in that area documented dented siding and multiple automobile hail dents on vehicles parked along County Road 12.

Damage was not uniform across the warning area. Streets with documented impacts include portions of Main Street in central Princeton and County Road 12 east of Winfield. Roof inspections conducted the same day by local assessors recorded surface scuffs and isolated shingle granule loss on asphalt shingles in at least five addresses within those corridors. No structural collapses were reported in the field data set. Vehicle claims filed to local insurers referenced hood and windshield pitting consistent with 1.0-inch to 1.25-inch hail in the zones identified by spotter reports.

Ground reports and radar indicate the highest concentration of impact occurred during the pre-dawn pulse and a late-morning reappearance of hail-producing cores. Areas inside the NWS warning polygons that lack ground reports showed minimal evidence of surface impact in follow-up street-level surveys conducted the same day.

Princeton, IA Hail Storm – May 2026

NWS WARNING AREAS · 64

What Happened

Damage Assessment

Storm Details

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