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Flood in Boundary County, Idaho
16 floods and flash floods events in the NCEI Storm Events record, 1950 to 2026. Event types counted: Flood, Flash Flood, Coastal Flood, Lakeshore Flood.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. Storm records through 30 Jun 2026.
NCEI records 16 flood events in Boundary County, Idaho, between 1950 and 2026, spread over 10 years.
March is the busiest month, with 4 of the recorded events. The last 20 years account for 13 events against 3 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 2% of the 790 flood events recorded in Idaho; its 1.3 per 100 square miles compares with 1.0 statewide.
Compared with Idaho
| Measure | Boundary County | Idaho | US |
|---|---|---|---|
| Flood events since 1950 | 16 | 790 | 183,559 |
| Per 100 square miles | 1.3 | 1.0 | 5.2 |
| Per 10,000 residents | 12.7 | 4.2 | 5.5 |
| Deaths recorded | 0 | 3 | 2,961 |
| Busiest month | March | June | June |
By year
Seasonality
1Feb
1Mar
4Apr
1May
4Jun
2Jul
1Aug
0Sep
0Oct
0Nov
0Dec
2
Recorded events
All 16 events, most recent first. Magnitude is hail size, tornado rating or wind speed as recorded.
| Date | Event type | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|
| 10 Dec 2025 | Flood | — | $2K | — | — | — | County |
| 21 May 2023 | Flash Flood | — | $500 | — | — | — | County |
| 7 May 2018 | Flood | — | $2K | — | — | — | County |
| 9 Dec 2015 | Flood | — | — | — | — | — | County |
| 7 Feb 2015 | Flood | — | — | — | — | — | County |
| 5 Mar 2014 | Flood | — | $25K | — | — | — | County |
| 11 Jan 2014 | Flood | — | $5K | — | — | — | County |
| 1 Jul 2012 | Flood | — | — | $4.0M | — | — | County |
| 30 Mar 2012 | Flood | — | — | — | — | — | County |
| 30 Mar 2012 | Flood | — | — | — | — | — | County |
| 15 Mar 2012 | Flood | — | $50K | — | — | — | County |
| 6 Apr 2011 | Flood | — | $500K | — | — | — | County |
| 19 May 2008 | Flood | — | — | — | — | — | County |
| 16 Jun 2006 | Flood | — | — | — | — | — | County |
| 29 Jun 1998 | Flash Flood | — | — | — | — | — | County |
| 26 May 1998 | Flash Flood | — | $500K | — | — | — | County |
Questions and answers
How many flood events has Boundary County had?
16 events in the NCEI Storm Events record between 1950 and 2026. Reporting of floods and flash floods became far more complete after 1996, so early decades undercount.
When was the last recorded flood event in Boundary County?
10 Dec 2025 (Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Boundary County?
The flood of 1 Jul 2012, with property damage estimated by NCEI at $0 and crop damage at $4.0M.
How does Boundary County compare with Idaho for flood?
1.3 events per 100 square miles against 1.0 statewide; the county holds 16 of the state's 790 recorded events.
Provenance
NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026, public domain. County-recorded events plus zone-recorded events whose forecast zone is named for the county (marked "Forecast zone"). Population and area from the US Census Bureau (2021). Built 1 Oct 2026. See the methodology, the Flood hub and the county page.