Hail HistoryHome › Montana › Jefferson County
Hail history for Jefferson County, MT
43 hail reports in Jefferson County since 2006 on 25 days. The largest stones measured 1.5 in (ping pong ball) on Aug 10, 2019.
Cities in Jefferson County
Recent hail in Jefferson County
| Date | Hail size | Where |
|---|---|---|
| Jul 16, 2026 | 1 in quarter | Clancy 2 hail reports |
| Jul 28, 2025 | 1 in quarter | Clancy 1 hail report |
One row per day: the largest hail reported in the county that day, the places and the number of reports.
Hail days in Jefferson County by year
When hail season peaks in Jefferson County
Damaging thunderstorm winds in Jefferson County
20 reports of damaging thunderstorm wind in Jefferson County since 2006, on 13 days. The strongest measured gust was 79 mph on Sep 5, 2013.
| Date | Strongest gust | Where |
|---|---|---|
| Sep 2, 2026 | 62 mph, measured | Boulder, Wickes, East Helena 4 wind reports |
| Jul 30, 2026 | 54 mph, measured | Boulder 1 wind report |
| Jul 24, 2026 | 51 mph, measured | Boulder 1 wind report |
| Sep 14, 2025 | 61 mph, measured | Boulder Airport 1 wind report |
| Jul 9, 2025 | 58 mph, measured | Louisville 1 wind report |
| Aug 19, 2024 | 62 mph, measured | Louisville 2 wind reports |
| Jun 21, 2018 | 58 mph, measured | Boulder 1 wind report |
| Jul 5, 2017 | 60 mph, estimated | Basin 1 wind report |
| Aug 7, 2016 | 58 mph, measured | Whitehall 1 wind report |
| Sep 5, 2013 | 79 mph, measured | Boulder Airport, Piedmont, Whitehall 4 wind reports |
Severe thunderstorm wind means gusts of 58 mph or more, or wind that caused damage. Measured gusts come from weather stations; estimated ones from spotters and damage surveys.
Filing a roof or car hail claim?
Insurers ask for the date of loss. The dates on this page are when hail was reported near Jefferson County; hail can hit one street and miss the next, so a report is not proof of damage at your address. A licensed roofer or your insurance adjuster can inspect the roof. Many policies set a time limit for filing a claim — check yours.
Data: NOAA NCEI Storm Events Database (final records through Jun 30, 2026) and National Weather Service Local Storm Reports (preliminary, since then).