Ada County, Idaho
County storm and disaster record · FIPS 16001 · population 494,805 · 1,052 sq mi
NOAA's Storm Events Database holds 308 records for Ada County, Idaho from 1950 through June 30, 2026, on 222 days; the most frequent are severe thunderstorm wind events (117 records). The deadliest single record is the August 25, 2008 wildfire, filed for the forecast zone Upper Treasure Valley, which covers the county: 1 death and $6.9 million in damage in 2025 dollars. FEMA has issued 6 declarations naming the county since 1964, 4 of them for natural hazards; the latest for a natural hazard was “Flooding” on October 7, 2017.
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
- 308on 222 days, 1950 to June 30, 2026
- Deaths recorded
- 185 injuries
- Damage, 2025 dollars
- $16Mas filed (scale steps before 1993)
- Tornadoes
- 13strongest F1
- FEMA declarations
- 6latest 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 Ada County most?
The most frequent records are severe thunderstorm wind events: 117 since 1958. 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 |
|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 117 | 90 | 1958-2026 | 0 | 76 | $1.1M | 2 of 44 |
| Winter storms | 45 | 38 | 1996-2025 | 0 | 7 | – | 39 of 44 |
| Hail | 41 | 33 | 1967-2024 | 0 | 1 | $10K | 5 of 44 |
| High wind and dust storms | 30 | 27 | 1997-2026 | 0 | 0 | $141K | 23 of 44 |
| Floods | 24 | 23 | 1997-2025 | 0 | 0 | $6.9M | 6 of 44 |
| Heavy rain | 17 | 9 | 1996-2024 | 0 | 0 | – | 2 of 44 |
| Tornadoes | 13 | 10 | 1956-2023 | 0 | 0 | $143K | 6 of 44 |
| Fog, smoke and funnel clouds | 8 | 8 | 1997-2021 | 0 | 1 | – | 10 of 44 |
| Wildfires | 6 | 6 | 1997-2015 | 1 | 0 | $7.7M | 27 of 44 |
| Landslides and avalanches | 3 | 1 | 2025-2025 | 0 | 0 | – | 26 of 44 |
| Lightning | 3 | 3 | 1997-1999 | 0 | 0 | $18K | 8 of 44 |
| Extreme cold | 1 | 1 | 2002-2002 | 0 | 0 | – | 34 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.
How many tornadoes has Ada County had?
NOAA records 13 tornadoes in Ada County from 1956 to 2023, the strongest rated F1, with 0 deaths and 0 injuries recorded in the county. That is 6th of 44 Idaho counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 13 tornadoes whose track touched Ada County since 1950 (NOAA's county records number 13, the same count); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in Idaho.
Every tornado record filed for Ada County (13)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2023-05-26 | Star, Ada County | EF0 0.95 mi x 3 yd | 0 | 0 | – |
| 2000-08-03 | Eagle, Ada County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 2000-08-03 | Gowen Field Boise, Ada County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 2000-08-03 | Gowen Field Boise, Ada County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 2000-08-03 | Gowen Field Boise, Ada County | F0 | 0 | 0 | – |
| 2000-07-18 | Kuna, Ada County | F0 0.1 mi x 15 yd | 0 | 0 | – |
| 1998-05-10 | Gowen Field Boise, Ada County | F0 2 mi x 50 yd | 0 | 0 | – |
| 1997-04-20 | Boise Terminal Airport, Ada County | F0 0.2 mi x 30 yd | 0 | 0 | – |
| 1984-10-26 | Ada County | F1 0.3 mi x 50 yd | 0 | 0 | $25K step |
| 1984-03-21 | Ada County | F1 0.1 mi x 3 yd | 0 | 0 | $25K step |
| 1967-06-02 | Ada County | 0 | 0 | – | |
| 1956-08-23 | Ada County | F0 0.5 mi x 100 yd | 0 | 0 | $30 step |
| 1956-07-09 | Ada County | F1 | 0 | 0 | $30 step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Ada County?
The most recent record with damage, injuries or deaths is the June 6, 2023 flash flood ($1.9 million in damage in 2025 dollars).
Thunderstorms produced heavy rain across portions of the Lower Treasure Valley, including the city of Boise. Social media, weather spotter, and emergency manager reports indicated localized flooding.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1108868)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-05-28 | Thunderstorm WindKuna, Ada County | 52 kt wind | 0 | 0 | – |
| 2026-05-28 | Thunderstorm WindGowen Field Boise, Ada County | 51 kt wind | 0 | 0 | – |
| 2026-05-28 | Thunderstorm WindBoise Terminal Airport, Ada County | 59 kt wind | 0 | 0 | – |
| 2026-05-28 | Thunderstorm WindKuna, Ada County | 63 kt wind | 0 | 0 | – |
| 2026-05-25 | Thunderstorm WindFloating Feather Arp, Ada County | 50 kt wind | 0 | 0 | – |
| 2026-05-25 | Thunderstorm WindBoise Hills Vlg, Ada County | 51 kt wind | 0 | 0 | – |
| 2026-05-25 | Thunderstorm WindGowen Field Boise, Ada County | 52 kt wind | 0 | 0 | – |
| 2026-05-25 | Thunderstorm WindMeridian, Ada County | 50 kt wind | 0 | 0 | – |
| 2026-05-13 | High WindAda County and 2 more · forecast zone Upper Treasure Valley | 53 kt wind | 0 | 0 | – |
| 2026-05-13 | High WindAda County and 2 more · forecast zone Upper Treasure Valley | 56 kt wind | 0 | 0 | – |
| 2025-12-17 | High WindAda County and 2 more · forecast zone Upper Treasure Valley | 57 kt wind | 0 | 0 | – |
| 2025-12-17 | Thunderstorm WindOrchard, Ada County | 57 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 |
|---|---|---|---|---|---|
| 2008-08-25 | WildfireAda County and 2 more · forecast zone Upper Treasure Valley A wildfire in Southeast Boise caused by an electrical component near an Idaho Power sub station quickly burned out of control destroying 10 homes and damaging many more including 1 fatality. Another wildfire near Mountain Home burned around 500 acres. | 1 | 0 | $6.9M | |
| 2010-08-21 | Thunderstorm WindGowen Field Boise, Ada County The BOI ASOS measured a wind gust of 68 MPH and several reports were received for wind damage including downed trees and power lines. Minor injuries were reported from the Western Idaho Fair as a result of temporary structures collapsing. | 59 kt wind | 0 | 70 | – |
| 2023-01-18 | Heavy SnowAda County and 2 more · forecast zone Upper Treasure Valley The Ada County Sheriff attributed 48 total traffic accidents to the snowfall and resulting slippery road conditions. | 0 | 7 | – | |
| 2002-07-25 | Thunderstorm WindMeridian, Ada County Thunderstorm winds brought down trees and power lines which left over 5000 homes and businesses without power. Winds also kicked up dust which reduced visibility to near zero on Interstate 84 near Blacks Creek Road. This resulted in a 12 car pileup in which four persons were injured. Wind gusts were measured at 62 mph ... | 54 kt wind | 0 | 4 | – |
| 2019-10-19 | Thunderstorm WindKuna, Ada County The public in Kuna reported several large trees, power lines and fences down, and car damage. The Boise Fire Department reported a lightning strike on a house 2 miles east of Boise. Two injuries were reported including two dogs that died in the fire. | 61 kt wind | 0 | 2 | – |
| 2013-02-05 | Dense FogAda County and 2 more · forecast zone Upper Treasure Valley Numerous reports of slide offs, roll overs and crashes due to dense fog and freezing rain in the area. | 0 | 1 | – | |
| 1995-07-09 | HailBlack Creek, Ada County | 1.50 in hail | 0 | 1 | $10K |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2008-08-25 | WildfireAda County and 2 more · forecast zone Upper Treasure Valley | 1 | 0 | $6.9M | |
| 2017-05-01 | FloodBarber, Ada County | 0 | 0 | $2.4M | |
| 2023-06-06 | Flash FloodBoise, Ada County | 0 | 0 | $1.9M | |
| 2017-03-06 | FloodBarber, Ada County | 0 | 0 | $1.2M | |
| 2017-04-01 | FloodBarber, Ada County | 0 | 0 | $1.2M | |
| 1995-04-27 | Thunderstorm WindStar, Ada County | 0 | 0 | $968K | |
| 2010-07-28 | WildfireAda County and 2 more · forecast zone Upper Treasure Valley | 0 | 0 | $677K | |
| 1995-07-09 | HailBlack Creek, Ada County | 1.50 in hail | 0 | 1 | $10K |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $25K, in the dollars of the day) holds: March 21, 1984 (tornado, Ada County); October 26, 1984 (tornado, Ada County).
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 Ada 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 |
|---|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 2 | 3 | 6 | 15 | 21 | 20 | 15 | 35 |
| Winter storms | – | – | – | – | 6 | 5 | 12 | 22 |
| Hail | 0 | 1 | 2 | 6 | 14 | 9 | 4 | 5 |
| High wind and dust storms | – | – | – | – | 2 | 10 | 6 | 12 |
| Floods | – | – | – | – | 6 | 3 | 9 | 6 |
| Heavy rain | – | – | – | – | 1 | 0 | 0 | 16 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
Records by month in Ada County. The two busiest months are in violet.
The values, month by month
Jan 21 · Feb 15 · Mar 25 · Apr 29 · May 46 · Jun 41 · Jul 35 · Aug 52 · Sep 15 · Oct 5 · Nov 8 · Dec 16 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Ada County
FEMA's register lists 6 declarations that include Ada County: 4 major disasters, 2 emergencies and 0 fire management assistance declarations. Most were for biological (2) and flood (2).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-04-09 | DR-4534 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3467 | Biological | Covid-19 |
| 2017-10-07 | DR-4342 | Flood | Flooding |
| 2005-09-13 | EM-3244 | Hurricane | Hurricane Katrina |
| 2000-09-01 | DR-1341 | Fire | Wildfires |
| 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 Ada County had?
NOAA's Storm Events Database holds 24 flood or flash flood records for Ada County from 1997 to 2025, on 23 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Ada County ranks 1159th of 2,942 U.S. counties.
The National Flood Insurance Program has paid $499,000 on 133 claims filed in Ada County; the most in one year was 37 in 2017. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1979: 2 · 1980: 2 · 1982: 2 · 1983: 1 · 1984: 2 · 1986: 1 · 1989: 2 · 1992: 8 · 1996: 5 · 1997: 11 · 1998: 7 · 1999: 1 · 2000: 2 · 2001: 1 · 2004: 4 · 2005: 2 · 2006: 5 · 2007: 2 · 2008: 4 · 2009: 3 · 2010: 2 · 2011: 1 · 2012: 3 · 2013: 1 · 2014: 2 · 2015: 2 · 2016: 3 · 2017: 37 · 2019: 2 · 2020: 2 · 2021: 2 · 2022: 2 · 2023: 2 · 2024: 2 · 2025: 1 · 2026: 2; 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 Ada County
FEMA's National Risk Index rates Ada County Relatively Moderate overall, with an expected annual loss of $116 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 |
|---|---|---|---|
| Winter Weather | Very High | $3.0M | 8.9 a year (modeled) |
| Wildfire | Relatively High | $27M | once in about 87 years (modeled) |
| Strong Wind | Relatively High | $3.8M | once in about 3 years (modeled) |
| Lightning | Relatively High | $2.0M | 20 a year (modeled) |
| Heat Wave | Relatively Moderate | $7.0M | 4.4 modeled event-days a year |
| Riverine Flooding | Relatively Moderate | $63M | about once a year (modeled) |
| Ice Storm | Relatively Moderate | $706K | once in about 10 years (modeled) |
| Earthquake | Relatively Low | $6.6M | once in about 402 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Ada County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in IdahoEvery Idaho tornado since 1950 and the counties with the most per square mile
- Severe thunderstorm wind in IdahoThe state's severe thunderstorm wind events, 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 Ada CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Ada County's FEMA declarations (CSV)6 rows: every declaration that named the county, for your own analysis