Boise County, Idaho
County storm and disaster record · FIPS 16015 · population 7,582 · 1,899 sq mi
NOAA's Storm Events Database holds 254 records for Boise County, Idaho from 1950 through June 30, 2026, on 219 days; the most frequent are winter storm records (141 records). 155 of them are forecast-zone records, which the National Weather Service files once per zone: a county covered by several zones receives each one, so a single storm can add several records on the same day. The deadliest single record is the March 30, 2010 avalanche, filed for the forecast zone Boise Mountains, which covers the county: 2 deaths. FEMA has issued 7 declarations naming the county since 1964, 5 of them for natural hazards; the latest for a natural hazard was “Karney Fire” on September 18, 2012.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 254on 219 days, 1950 to June 30, 2026
- Deaths recorded
- 36 injuries
- Damage, 2025 dollars
- $10Mas filed (scale steps before 1993)
- FEMA declarations
- 7latest 2020
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Boise County most?
The most frequent records are winter storm records: 141 since 1996. 58% of its winter storm records since 1996 fell in December and January. The rank column places the county among Idaho's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Winter storms | 141 | 132 | 1996-2024 | 0 | 0 | – | 33 of 44 |
| Floods | 27 | 25 | 1997-2025 | 0 | 0 | $10M | 17 of 44 |
| Severe thunderstorm wind | 27 | 23 | 1970-2025 | 1 | 6 | $103K | 35 of 44 |
| Hail | 21 | 19 | 1961-2024 | 0 | 0 | – | 26 of 44 |
| Heavy rain | 19 | 10 | 1996-2024 | 0 | 0 | – | 6 of 44 |
| High wind and dust storms | 12 | 11 | 2006-2025 | 0 | 0 | $13K | 40 of 44 |
| Landslides and avalanches | 6 | 6 | 1997-2024 | 2 | 0 | – | 20 of 44 |
| Wildfires | 1 | 1 | 2002-2002 | 0 | 0 | – | 38 of 44 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
When was the last damaging storm in Boise County?
The most recent record with damage, injuries or deaths is the August 6, 2014 flood ($10.0 million in damage in 2025 dollars).
Middle Fork Road and many camping areas were closed due to flooding and mud slides.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 541159)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2025-12-17 | High WindBoise County and 2 more · forecast zone Boise Mountains | 61 kt wind | 0 | 0 | – |
| 2025-12-17 | High WindBoise County and 2 more · forecast zone Boise Mountains | 52 kt wind | 0 | 0 | – |
| 2025-10-25 | Thunderstorm WindHorseshoe Bend, Boise County | 52 kt wind | 0 | 0 | – |
| 2025-08-26 | Flash FloodGarden Vly, Boise County | 0 | 0 | – | |
| 2025-08-26 | Flash FloodLowman Warm Spgs Arp, Boise County | 0 | 0 | – | |
| 2025-06-11 | Flash FloodLowman, Boise County | 0 | 0 | – | |
| 2025-02-13 | Strong WindBoise County and 2 more · forecast zone Boise Mountains | 43 kt wind | 0 | 0 | – |
| 2014-08-06 | FloodIdaho City, Boise County | 0 | 0 | $10.0M | |
| 2010-08-21 | Thunderstorm WindIdaho City, Boise County | 61 kt wind | 1 | 0 | – |
| 2010-03-30 | AvalancheBoise County and 2 more · forecast zone Boise Mountains | 2 | 0 | – | |
| 2008-07-22 | Thunderstorm WindPlacerville, Boise County | 78 kt wind | 0 | 0 | – |
| 2003-08-22 | Thunderstorm WindLowman, Boise County | 70 kt wind | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2010-03-30 | AvalancheBoise County and 2 more · forecast zone Boise Mountains Two Washington state men died in an avalanche while snowmobiling about 17 miles north of McCall, Idaho. The size of the avalanche was estimated to be between 5 and 6 acres. | 2 | 0 | – | |
| 2010-08-21 | Thunderstorm WindIdaho City, Boise County Boise County Sherrif's dispatch reported a large number of trees down on and around Grimes Creek Road including one fatality at Grimes Creek. | 61 kt wind | 1 | 0 | – |
| 1993-08-07 | Thunderstorm WindBoise County | 0 | 4 | – | |
| 1993-08-10 | Thunderstorm WindBoise County Several large trees were downed near Robie Creek, 9 miles northeast of Boise. In Horseshoe Bend, 20 miles north of Boise, a woman sustained a head injury when she was struck by a portion of a metal roof torn free from a structure. | 0 | 1 | – | |
| 1987-06-15 | Thunderstorm WindBoise County | 0 | 1 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2014-08-06 | FloodIdaho City, Boise County | 0 | 0 | $10.0M |
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Boise County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Winter storms | – | – | – | – | 30 | 63 | 21 | 27 |
| Floods | – | – | – | – | 7 | 9 | 6 | 5 |
| Severe thunderstorm wind | 0 | 0 | 1 | 2 | 6 | 9 | 4 | 5 |
| Hail | 0 | 2 | 0 | 0 | 10 | 5 | 2 | 2 |
| Heavy rain | – | – | – | – | 3 | 0 | 0 | 16 |
| High wind and dust storms | – | – | – | – | 0 | 2 | 4 | 6 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
58% of its winter storm records since 1996 fell in December and January. The two busiest months are in violet.
The values, month by month
Jan 34 · Feb 26 · Mar 17 · Apr 9 · May 13 · Jun 24 · Jul 17 · Aug 19 · Sep 12 · Oct 4 · Nov 26 · Dec 53 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Boise County
FEMA's register lists 7 declarations that include Boise County: 4 major disasters, 2 emergencies and one fire management assistance declaration. Most were for biological (2) and fire (2).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-04-09 | DR-4534 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3467 | Biological | Covid-19 |
| 2012-09-18 | FM-5019 | Fire | Karney Fire |
| 2005-09-13 | EM-3244 | Hurricane | Hurricane Katrina |
| 2000-09-01 | DR-1341 | Fire | Wildfires |
| 1997-01-04 | DR-1154 | Severe Storm | Severe Storms, Flooding, Mud and Landslides |
| 1964-12-31 | DR-186 | Flood | Heavy Rains & Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Boise County had?
NOAA's Storm Events Database holds 27 flood or flash flood records for Boise County from 1997 to 2025, on 25 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Boise County ranks 2830th of 2,942 U.S. counties.
The National Flood Insurance Program has paid $36,000 on 1 claim filed in Boise County; the most in one year was 1 in 2017. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
2017: 1; the other years: 0.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Boise County
FEMA's National Risk Index rates Boise County Relatively Low overall, with an expected annual loss of $16.0 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Avalanche | Relatively High | $1.4M | once in about 10 years (modeled) |
| Landslide | Relatively Moderate | $356K | 2.1 a year (modeled) |
| Wildfire | Relatively Moderate | $8.2M | once in about 57 years (modeled) |
| Winter Weather | Relatively Low | $70K | 18 a year (modeled) |
| Riverine Flooding | Relatively Low | $5.5M | about once a year (modeled) |
| Strong Wind | Relatively Low | $225K | once in about 3 years (modeled) |
| Earthquake | Very Low | $158K | once in about 97 years (modeled) |
| Volcanic Activity | Very Low | $3 | once in about 5,000 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Boise County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Winter storms in IdahoThe state's winter storm records, by county, year and month
- The Idaho recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Boise CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Boise County's FEMA declarations (CSV)7 rows: every declaration that named the county, for your own analysis