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Flood in Bannock County, Idaho
62 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 62 flood events in Bannock County, Idaho, between 1950 and 2026, spread over 19 years.
August is the busiest month, with 20 of the recorded events. The last 20 years account for 37 events against 25 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 7.8% of the 790 flood events recorded in Idaho; its 5.6 per 100 square miles compares with 1.0 statewide.
Compared with Idaho
| Measure | Bannock County | Idaho | US |
|---|---|---|---|
| Flood events since 1950 | 62 | 790 | 183,559 |
| Per 100 square miles | 5.6 | 1.0 | 5.2 |
| Per 10,000 residents | 7.0 | 4.2 | 5.5 |
| Deaths recorded | 0 | 3 | 2,961 |
| Busiest month | August | June | June |
By year
Seasonality
1Feb
3Mar
1Apr
2May
7Jun
7Jul
10Aug
20Sep
11Oct
0Nov
0Dec
0
Recorded events
All 62 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 |
|---|---|---|---|---|---|---|---|
| 4 Jul 2025 | Flood | — | — | — | — | — | County |
| 14 May 2025 | Flash Flood | — | — | — | — | — | County |
| 17 Aug 2023 | Flash Flood | — | $1K | — | — | — | County |
| 30 May 2023 | Flash Flood | — | — | — | — | — | County |
| 30 Apr 2023 | Flood | — | $500 | — | — | — | County |
| 21 Sep 2022 | Flood | — | $1K | — | — | — | County |
| 18 May 2018 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2017 | Flood | — | $10K | — | — | — | County |
| 1 May 2017 | Flood | — | $65K | — | — | — | County |
| 4 Apr 2017 | Flood | — | — | — | — | — | County |
| 1 Mar 2017 | Flood | — | $125K | — | — | — | County |
| 5 Feb 2017 | Flood | — | $450K | — | — | — | County |
| 9 Jan 2017 | Flood | — | — | — | — | — | County |
| 8 May 2015 | Flash Flood | — | $2K | — | — | — | County |
| 14 Aug 2014 | Flash Flood | — | — | — | — | — | County |
| 13 Aug 2014 | Flash Flood | — | — | — | — | — | County |
| 8 Aug 2014 | Flash Flood | — | — | — | — | — | County |
| 5 Aug 2014 | Flash Flood | — | $6K | — | — | — | County |
| 11 Jul 2014 | Flash Flood | — | — | — | — | — | County |
| 8 Sep 2013 | Flash Flood | — | $1K | — | — | — | County |
| 3 Sep 2013 | Flash Flood | — | $700K | — | — | — | County |
| 23 Aug 2013 | Flash Flood | — | $500K | — | — | — | County |
| 7 Jul 2013 | Flash Flood | — | — | — | — | — | County |
| 22 Feb 2012 | Flood | — | $9K | — | — | — | County |
| 4 Jul 2011 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2011 | Flood | — | $10K | — | — | — | County |
| 8 May 2011 | Flood | — | — | — | — | — | County |
| 23 Aug 2009 | Flash Flood | — | $1K | — | — | — | County |
| 23 Aug 2009 | Flash Flood | — | $1K | — | — | — | County |
| 4 Jul 2009 | Flash Flood | — | $1K | — | — | — | County |
| 4 Jul 2009 | Flash Flood | — | $500K | — | — | — | County |
| 26 Jun 2009 | Flash Flood | — | $700K | — | — | — | County |
| 14 Jun 2009 | Flood | — | $25K | — | — | — | County |
| 14 Jun 2009 | Flash Flood | — | $8K | — | — | — | County |
| 24 Feb 2009 | Flood | — | $5K | — | — | — | County |
| 5 Sep 2007 | Flash Flood | — | — | — | — | — | County |
| 5 Sep 2007 | Flash Flood | — | — | — | — | — | County |
| 1 May 2006 | Flood | — | — | — | — | — | County |
| 21 Sep 2005 | Flash Flood | — | $5K | — | — | — | County |
| 22 Aug 2005 | Flash Flood | — | — | — | — | — | County |
| 17 Aug 2004 | Flash Flood | — | — | — | — | — | County |
| 18 Jul 2004 | Flash Flood | — | $535K | — | — | — | County |
| 24 Aug 2003 | Flash Flood | — | — | — | — | — | County |
| 22 Aug 2003 | Flash Flood | — | — | — | — | — | County |
| 3 Aug 2003 | Flash Flood | — | — | — | — | — | County |
| 27 Jul 1999 | Flash Flood | — | $30K | — | — | — | County |
| 30 Sep 1998 | Flood | — | — | — | — | — | County |
| 12 Sep 1998 | Flood | — | — | — | — | — | County |
| 12 Sep 1998 | Flash Flood | — | — | — | — | — | County |
| 11 Sep 1997 | Flash Flood | — | — | — | — | — | County |
| 7 Sep 1997 | Flash Flood | — | — | — | — | — | County |
| 22 Aug 1997 | Flash Flood | — | — | — | — | — | County |
| 12 Aug 1997 | Flood | — | — | — | — | — | County |
| 11 Aug 1997 | Flash Flood | — | — | — | — | — | County |
| 11 Aug 1997 | Flash Flood | — | — | — | — | — | County |
| 11 Aug 1997 | Flash Flood | — | — | — | — | — | County |
| 10 Aug 1997 | Flash Flood | — | — | — | — | — | County |
| 10 Aug 1997 | Flood | — | — | — | — | — | County |
| 28 Jul 1997 | Flood | — | — | — | — | — | County |
| 25 Jul 1997 | Flood | — | — | — | — | — | County |
| 18 Jun 1997 | Flood | — | — | — | — | — | County |
| 13 Jun 1997 | Flash Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has Bannock County had?
62 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 Bannock County?
4 Jul 2025 (Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Bannock County?
The flash flood of 26 Jun 2009, with property damage estimated by NCEI at $700K.
How does Bannock County compare with Idaho for flood?
5.6 events per 100 square miles against 1.0 statewide; the county holds 62 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.