Hail in Boulder, CO on May 18, 2025
Radar-estimated up to 1" (quarter size) · 2 ground reports
Weather radar estimated hail of up to 1" (quarter size) over Boulder between 3:07 PM and 3:19 PM, from 6 separate radar hail signatures inside the town. On the ground, 2 reports were filed in Boulder; the largest measured 1" (quarter size).
Ground reports filed in Boulder
| Time | Hail size | Source |
|---|---|---|
| 3:16 PM | 1" (quarter size) | NWS spotter report (public) |
| 3:15 PM | 0.75" (penny size) | NWS spotter report (public) |
What quarter-size hail does to a roof
One inch is the size where insurers and roofers start to expect shingle damage, especially on older roofs. Look for dented gutters and downspouts and granules collecting at the bottom of the downspouts. Radar describes the storm, not your shingles: the only way to know what a particular roof took is an inspection. Most homeowner policies set a deadline for reporting storm damage, so check your policy.
Every home inside a storm's radar footprint, scored by roof age, material and hail history, sold to a few roofers only so you are not the twentieth truck on the street.
Other Colorado towns hit on May 18
- Aurora, CO · May 18, 2025radar up to 1.75" (golf ball size) · 4 reports
- Louisville, CO · May 18, 2025radar up to 1.5" (ping-pong ball size)
- Broomfield, CO · May 18, 2025radar up to 1.25" (half dollar size)
- Erie, CO · May 18, 2025radar up to 1.25" (half dollar size)
- Lafayette, CO · May 18, 2025radar up to 1.25" (half dollar size)
- Mead, CO · May 18, 2025radar up to 1.25" (half dollar size) · 1 report
- Watkins, CO · May 18, 2025radar up to 1" (quarter size)
Other hail days in Boulder
Radar sizes are estimates from NEXRAD hail signatures (NOAA Severe Weather Data Inventory) for the largest stones in a storm cell, not a measurement at any one home. Ground reports are National Weather Service local storm reports and the NOAA Storm Events Database, as filed. Town-level data only; this page shows no addresses and no homeowner information.