Flagstaff, AZ Hail Storm – August 2026

Flagstaff, AZ — August 20, 2026. Midday into early evening thunderstorms produced a hail-bearing storm across the Flagstaff metro, with peak hail measured at 2.09 inches.

What Happened

The event spanned from midday into early evening and was documented in six NWS warning areas tied to radar detections. The NWS issued successive alert polygons as the hail-producing cells moved across the metro. Key alerts for the storm sequence were:

• August 20 · 12:49 PM MST (19:49 UTC) — 1.55 in hail reported by dual-polarization radar in an NWS warning area.
• August 20 · 2:38 PM MST (21:38 UTC) — 1.8 in hail detected by dual-polarization radar in a subsequent NWS warning area.
• August 20 · 3:30 PM MST (22:30 UTC) — 1.02 in radar-detected hail in an expanded warning area.
• August 20 · 4:05 PM MST (23:05 UTC) — 1.00 in radar-detected hail within the NWS warning area.
• August 20 · 5:00 PM MST (00:00 UTC) — 1.67 in hail detected by dual-polarization radar in an advisory polygon.
• August 20 · 5:08 PM MST (00:08 UTC) — 1.00 in radar-detected hail in the final warning area for this event.

All six alerts were issued as NWS warning areas and were based on dual-polarization radar detection. The warning areas tracked the primary storm corridor across the Flagstaff metro from roughly midday through early evening. Field reports remain limited; the radar record shows multiple cores producing hail as the system propagated east-southeast through the metro.

Damage Assessment

Radar-detected hail across the metro ranged from near 1.0 in up to the peak reported size. Hail at or above 1.0 in commonly produces cosmetic and functional damage to exterior building materials and vehicles. Hail approaching 2.09 in has sufficient mass to dent vehicle panels, crack solar panels, fracture skylights, and penetrate softer roofing products.

Inspectors and adjusters should prioritize vehicles parked in the storm path, asphalt shingle roofs, rooftop-mounted equipment, and exposed glass. Photographic documentation with timestamps and location references is critical. Localized severity will vary across the metro according to the NWS warning areas and radar hail swath.

What Contractors Should Know

Begin with a targeted exterior survey in the NWS warning areas that covered the Flagstaff metro on August 20. Check shingles, gutters, vents, HVAC condensers, and solar arrays for impact damage. Capture geotagged photos and short video of affected elements. Record the local alert times and any on-site observations to link claims to the storm timeline.

Plan repair crews for staged response. Triage obvious safety hazards first, such as broken glass and damaged roofing that allows water intrusion. Use tarps only where immediate repair is required to prevent further loss. Provide clients clear scopes of work with line-item estimates for replacement versus repair of panels, shingles, and vehicle surfaces.