Great Falls, MT Hail Storm – August 2026

Great Falls, MT experienced a multi-zone hail event on August 27, 2026 with a peak hail size of 0.87 inches. The event moved across the metro in late afternoon into early evening and is now concluded.

What Happened

A sequence of three NWS warnings covered the Great Falls metro during the event. The first warning issued at 5:21 PM MDT reported 0.75 inch hail in the first NWS warning area. A second warning followed at 6:51 PM MDT again reporting 0.75 inch hail for a downstream warning area. The third warning issued at 7:42 PM MDT maintained the same 0.75 inch hail report for a further warning area. The alerts produced a multi-zone warning area that migrated east-southeast across the metro between late afternoon and early evening.

NWS products for each warning used the NWS warning only classification for hail size. Ground reports and local sensors produced a maximum recorded hail diameter of 0.87 inches within the aggregated metro footprint. The storm is no longer active within the Great Falls warning area.

Damage Assessment

Hail in the 0.75–0.87 inch range typically causes cosmetic impacts to soft metals and siding. Vinyl siding can show surface pitting and small holes where hail struck at full size. Asphalt shingle granule loss will occur on exposed roof slopes where hail struck directly. Vehicles parked without cover can have paint chips and small dents concentrated on horizontal surfaces.

Glass breakage is unlikely at this diameter but existing windshield chips can be enlarged into stress fractures when struck. Landscaping and agricultural foliage will show bruising and punctures on leaves and soft fruit. Gutters, screens, and exterior trim are the most common minor-loss items observed after similar events in Great Falls.

What Contractors Should Know

Inspect roofs, gutters, and soft-metal trim first in the areas covered by the three NWS warning areas. Use time-stamped photos and scale references for every roof and vehicle inspected. Focus initial roof checks on granule loss, exposed mat, and denting around vents and flashing. Record the warning-area time windows and the 5:21 PM MDT, 6:51 PM MDT, and 7:42 PM MDT NWS warnings in each job file.

For temporary work, secure loose screens and repair isolated holes in vinyl siding to prevent water intrusion when rainfall follows hail. Provide itemized estimates that separate cosmetic repairs from functional repairs. Note that insurers often require evidence tied to the warning area and the local inspection time. Coordinate scheduling to document progressive deterioration and to avoid redundant work.

See the Strike Map for the radar-confirmed hail swath and the damage zone outline available with our paid product.