Flash Flood in Idaho
Every flash flood event the National Weather Service has filed in Idaho, year by year, with the most significant episodes. Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
The most significant on the map
The most significant flash flood episodes in Idaho.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The record
- Events
- 322
- Deaths
- 2
- Injuries
- 1
- Damage
- $34 million
Every year
The most significant
Ranked by deaths, injuries, damage and size together.
- Flash Flooding and Winter Storm in Idaho, February 2 to 28, 1999Heavy snow of 6-15" each day was reported across portions of north Idaho. Some of the sites included: Sandpoint, Potlatch, St. Maries, Kellogg and Winchester. The heavy snow caused hazardous driving conditions and several accidents on area roadways.
- Flash Flood and Damaging Winds in Idaho, June 9, 2023A slow moving thunderstorm moved over the Lewiston Idaho area and caused flash flooding. The KLWS ASOS recorded 0.68 inches of rain from 1250LST to 1356LST. Strong winds also knocked down several trees in Latah County.
- Flash Flood in Idaho, July 29, 1996Heavy rain produced flash flooding with water 3 to 4 feet deep across the east bound lanes of Interstate 84 near mile marker 261. A driver rounded a corner and drove into the flooded area.
- Flash Flooding in Idaho, June 6, 2009A cold front moving through Idaho and the attendant moisture lead to showers and thunderstorms that produced local rainfall amounts of one inch per hour and flash flooding in Southwest Idaho.
- Flash Flood and Flooding in Idaho, June 1 to 30, 2017Winter snow melt and river flooding continued throughout much of June with Blaine and Custer counties receiving the worst of it.
- Flash Flood in Idaho, April 14, 2024Abundant moisture and instability, along with weak steering flow resulted in slow moving thunderstorms containing heavy rain during the evening.
- Flash Flood in Idaho, June 26, 2026Following a morning cold front, clearing skies allowed for weak to moderate instability (500-1000 j/kg of CAPE) to build in across SW Idaho. With an upper trough just to the west, dynamics and kinematics were favorable for thunderstorm development.
- Flash Flooding and Flooding in Idaho, June 3 to 11, 2010A deep low pressure system anchored in the Gulf of Alaska and a zonal flow pattern across the Pacific Northwest and Intermountain West provided the right ingredients for a sustained moisture plume which produced convection and periods of moderate to heavy rain over a three day…
- Flash Flood and Damaging Winds in Idaho, June 6 to 7, 2023Thunderstorms developed across southwest Idaho early Tuesday evening and produced |heavy rain and strong winds across portions of the Lower Treasure Valley, including the city of Boise.
- Flash Flood in Idaho, May 8, 2005A slow moving thunderstorm moved 2 miles east of the town of Lapwai on the afternoon of the 8th of May. An estimated 2 to 3 inches fell across the headwaters of Garden Gulch Creek in about an hour.
- Flash Flooding in Idaho, May 6, 2005On the evening of the 6th of May, a slow moving line of thunderstorms moved across central Idaho. These thunderstorms dumped one to three inches of rain in an hour across portions of the Idaho Palouse.
- Flash Flooding and Hail in Idaho, May 23, 2023Widespread severe weather with strong winds, large hail, and very heavy rains occurred on the 23rd in the Snake River Plain.
- Flash Flooding and Wildfire in Idaho, July 2 to 31, 1998a 2 acre wildfire threatened St. Maries High School.
- Flash Flood and Hail in Idaho, June 26, 2009Flooding occurred in Pocatello with large hail reported in southeast Idaho.
- Flash Flood in Idaho, June 7, 2010Yet another abnormally moist Pacific weather system brought heavy rain to portions of Idaho County. Rainfall rates nearing an inch per hour were recorded with this system. Flash flooding occured washing out area roads.
- Flash Flooding in Idaho, September 3, 2013The most significant flooding took place in Pocatello and Chubbuck in Bannock County, the second major flood in two weeks.
- Flash Flooding and Heavy Rain in Idaho, May 26 to 27, 19983 inches of rain overnight
- Flash Flood and Hail in Idaho, August 1, 2013A 40 to 50 knot mid-level southwest jet maximum combined with unstable conditions over Lemhi County helped initiate a large supercell thunderstorm that brought wind and hail.
- Flash Flood in Idaho, July 15, 2014A thunderstorm dropped anywhere from 1 to 3 inches in the city of Rexburg. A single thunderstorm cell moved over the city and heavy rain began at around 5:30 pm MDT and brought the 1 to 3 inch rainfall. Main Street was shut down with over a foot of running water on it.
- Flash Flooding and Hail in Idaho, July 4, 2009Strong thunderstorms on July 4th caused flooding in Inkom and Pocatello and large hail fell also.
- Flash Flood in Idaho, July 18, 2004Extremely heavy rain...approximately 2 inches fell in 45 minutes from 3 to 4 pm MDT in Pocatello and caused extensive flooding especially along the east benches. The Center Street underpass had a foot of water covering it.
- Flash Flood in Idaho, August 23, 2013Heavy rain with 2 to 4 inch amounts in the Chubbuck and Pocatello area caused extensive street, business and home flooding on August 23rd. The Center Street underpass was closed.
- Flash Flood and Debris Flow in Idaho, April 9 to 11, 2019Beginning on April 6th and continuing through April 10th a series of Pacific atmospheric rivers were directed into Oregon, southeast Washington and central Idaho saturating the ground with heavy rainfall.
- Flash Flood in Idaho, February 28, 2006Heavy rains combined with melting snow to cause extensive flooding in Rexburg and throughout Madison County. Several roads washed out county wide and extensive basement flooding was reported in several houses in Rexburg.
- Flash Flooding in Idaho, August 6, 2014A second consecutive day of heavy rainfall in southeastern Idaho caused flash flooding mainly in Blaine, Power, and Bingham Counties. The worst of the flooding occurred in the city of Blackfoot.
More
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.