Sioux County
Residents 36,554Deaths 2024 3Deaths 2015–2024 37Latest data year 2024
FARS data are based on police crash reports and other sources; the drunk-driving measure is based on the highest BAC of any driver in the crash. Latest data year: 2024. Figures are aggregates from NHTSA's Fatality Analysis Reporting System; no individual crash is identified.
In 2024, the latest year in FARS, Sioux County (Iowa) had fewer than three fatal crashes with 3 deaths. Across the ten years 2015–2024 the county recorded 34 fatal crashes and 37 deaths.
With 36,554 residents, that is 10.4 deaths per 100,000 people a year over the ten years, close to the Iowa rate of 10.9 and close to the national rate of 11.8.
The ten-year death toll fell 24% from 49 in 2005–2014 to 37 in 2015–2024.
Of the factors FARS records, the one that stands furthest above the state share here is speeding: 17.6% against 20.2% for Iowa.
32% of the county's fatal crashes happened between noon to 6pm, and Monday was the most common day (21%).
Trend since 1975
Ten-year total down 24% (49 in 2005–2014, 37 in 2015–2024). The shaded band is the ten-year window used for rates and shares. County codes are matched to today's Census county list; a few historic code changes are merged.
Compared with Iowa and the nation
| Measure | Sioux | Iowa | United States |
|---|---|---|---|
| Deaths per 100,000 residents a year, 2015–2024 | 10.4 | 10.9 | 11.8 |
| Deaths per 100,000 residents, 2024 | 8.2 | 11.0 | 11.5 |
| Deaths, 2015–2024 | 37 | 3,477 | 389,190 |
| Fatal crashes, 2015–2024 | 34 | 3,140 | 358,460 |
| Deaths per fatal crash | 1.1 | 1.1 | 1.1 |
| Change vs previous ten years | -24% | -10% | +7% |
| Crashes on rural roads | 94% | 72% | 43% |
Rates divide deaths by Census Bureau population estimates for each year (residents, not road users; through traffic on major routes raises the rate of small counties). Population 36,554 in 2024.
Factors
"Alcohol" counts crashes where police reported at least one driver as drinking (FARS DR_DRINK), not the BAC-based alcohol-impaired measure NHTSA publishes separately. "Speeding" counts crashes with a driver coded as racing, exceeding the limit or too fast for conditions. Details in the methodology. Factor pages: alcohol, speeding, pedestrians, motorcycles, unrestrained occupants.
Time of day and day of week
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Fatal crashes in Sioux County by weekday and hour, 2015–2024: darker cells are busier. 34 crashes with a known hour and weekday.
By weekday
Light condition
Road type
FHWA functional classes as coded in FARS (FUNC_SYS), share of fatal crashes with a reported class; tick marks the Iowa share. Interstates and other principal arterials carry the most traffic, so a high share there is expected. See what the road classes mean.
Weather
Routes with the most fatal crashes in Sioux
| # | Route | Type | In county | Fatal crashes | Deaths | Alcohol | Speeding |
|---|---|---|---|---|---|---|---|
| 1 | US Route 75 | US highway | 5 | 25 | 26 | 24% | 8% |
| 2 | US Route 18 | US highway | 4 | 41 | 48 | 17% | 7% |
Signed routes (Interstate, US and state highways) that have a page on this site, ranked by fatal crashes in this county over 2015–2024; "fatal crashes" and "deaths" columns are the statewide totals for the route. Local streets and county roads are not listed.
By year, 2015–2024
| Year | Fatal crashes | Deaths | Drinking-driver crashes | Per 100,000 | |
|---|---|---|---|---|---|
| 2024 | 1–2 | 3 | 0 | 8.2 | IA 2024 |
| 2023 | 6 | 6 | 1–2 | 16.4 | IA 2023 |
| 2022 | 6 | 8 | 0 | 21.9 | IA 2022 |
| 2021 | 3 | 3 | 1–2 | 8.2 | IA 2021 |
| 2020 | 3 | 3 | 0 | 8.2 | IA 2020 |
| 2019 | 1–2 | 1–2 | 0 | — | IA 2019 |
| 2018 | 1–2 | 1–2 | 1–2 | — | IA 2018 |
| 2017 | 3 | 3 | 1–2 | 8.2 | IA 2017 |
| 2016 | 4 | 4 | 1–2 | 10.9 | IA 2016 |
| 2015 | 3 | 3 | 0 | 8.2 | IA 2015 |
Counts under three are shown as "1–2" (small-count rule). Per-100,000 uses the 2024 population for every year in this table; the ten-year rate above uses each year's estimate.
Questions and answers
How many people died in crashes in Sioux County, Iowa?
3 people died in fewer than three fatal crashes in 2024; 23 over 2020–2024 and 37 over 2015–2024, according to NHTSA's Fatality Analysis Reporting System.
How does Sioux compare with Iowa?
10.4 deaths per 100,000 residents a year over 2015–2024, against 10.9 for Iowa and 11.8 nationally. Rates use Census Bureau population estimates.
What share of fatal crashes in Sioux involved alcohol?
17.6% of fatal crashes in 2015–2024 had at least one driver reported by police as drinking, against 25.4% in Iowa. The factor furthest above the state share was speeding at 17.6%.
Which roads in Sioux see the most fatal crashes?
Among signed routes with a page on this site, US Route 75 (5 fatal crashes in the county, 2015–2024) and US Route 18 (4 fatal crashes in the county, 2015–2024).
When do fatal crashes happen in Sioux?
Most often between noon to 6pm (32% of crashes) and on Mondays (21%); 44.1% happened after dark.
Where does this data come from?
NHTSA's Fatality Analysis Reporting System annual files (1975–2024) and Census Bureau county population estimates. Figures are aggregates; no individual crash is identified. See the methodology page for definitions.
Provenance
Source: National Highway Traffic Safety Administration, Fatality Analysis Reporting System, annual national CSV files 1975–2024 (accident table for every year; vehicle and person tables for 2015–2024), public domain. Population: US Census Bureau, Population Estimates Program, county totals (vintages 2000–2010, 2010–2020 and 2020–2024). Data through 31 Dec 2024; page generated 30 Sep 2026. Processing errors are corrected at the next build; see corrections and sources.