Hays, MT Hail Storm – May 2026

Hays, MT recorded radar-detected hail on May 29, 2026, peaking at 2.06 inches. The multi-zone storm produced recurring radar hail alerts and an NWS warning across late afternoon and early evening.

What Happened

Five NWS alerts covered the event in and around Hays on May 29. The sequence began in the late afternoon and continued into early evening, with dual-polarization radar detecting multiple discrete hail cores and one NWS warning issued in the middle of the event. The alerts were:

• May 29 · 4:22 PM MDT (22:22 UTC) – 1.75-inch hail detected by dual-polarization radar in the NWS alert area.
• May 29 · 4:43 PM MDT (22:43 UTC) – 1.65-inch hail detected by dual-polarization radar in the NWS alert area.
• May 29 · 6:13 PM MDT (00:13 UTC) – 2.06-inch hail detected by dual-polarization radar in the NWS alert area.
• May 29 · 6:42 PM MDT (00:42 UTC) – 0.75-inch hail reported in an NWS warning only for part of the alert area.
• May 29 · 7:09 PM MDT (01:09 UTC) – 2.02-inch hail detected by dual-polarization radar in the NWS alert area.

The sequence shows repeated radar-detected hail cores passing through the same general corridor. The event is concluded.

Damage Assessment

Observed sizes ranged from approximately 0.75 inch to 2.06 inches within the Hays alert area. Hail above 1.5 inches commonly causes denting on vehicle body panels and can fracture single-pane glass. Hail at or above 2.0 inches can cause significant impact damage to asphalt roofing, skylights, and unprotected mechanical equipment on rooftops.

For properties along the radar-detected hail path in Hays, expect granule loss and bruising on composite shingles, scuffed or dented metal roofing and trim, and localized broken glass on exposed windows or skylights. Smaller 0.75-inch hail in peripheral parts of the warning area is more likely to cause cosmetic siding damage and chipped exterior paint than structural failures.

What Contractors Should Know

Prioritize exterior inspections in the areas the NWS alerts covered and along the radar-detected hail cores. On roofs, inspect for granule loss, shingles with rounded or pitted indentations, and broken flashing. Photograph damage with a scale reference and record precise locations and local times for each observation. For vehicles and outdoor equipment, document dent patterns and punctures and tag affected units with the same location details.

Estimate replacement needs for shingles and skylights where impact evidence reaches or exceeds 2.0 inches. For dented metal roofing and HVAC fins, assess whether straightening and cosmetic repair are sufficient or if component replacement is required. Coordinate with property owners and insurers on temporary weatherproofing measures when interior exposure is observed. Maintain crew safety protocols for wet and debris-covered surfaces.