Sioux City, Iowa: natural disaster risk
How exposed Sioux City is to floods, storms and other hazards, from FEMA and NOAA records for Woodbury County.
Sioux City is a city of 86,101 people in Woodbury County, Iowa. Parts of Sioux City also reach into Plymouth County. FEMA's National Risk Index rates Woodbury County relatively moderate for natural hazards overall, about average for the US. The costliest hazards there are inland flooding, tornado and cold wave, with about $50.7 million in expected losses a year across the county. The weather service has logged 899 storm reports in the county since 1953, including 61 tornadoes and 80 floods. About 0.5% of homes in the county carry federal flood insurance.
Risk figures are for Woodbury County, the county with most of the population Sioux City sits in. FEMA National Risk Index December 2025; NOAA Storm Events; US Census Bureau ACS 2020 to 2024. Updated November 6, 2026.
Top risks in Sioux City
Full Woodbury County report ›- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
- Turn on emergency alerts on your phone and keep a weather radio.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
All hazards
| Hazard | Rating | A year |
|---|---|---|
| Inland flooding | $18M | |
| Tornado | $16M | |
| Cold wave | $6M | |
| Hail | $3M | |
| Heat wave | $2M | |
| Drought | $2M | |
| Strong wind | $2M | |
| Wildfire | $932K | |
| Ice storm | $631K | |
| Winter weather | $293K | |
| Lightning | $250K | |
| Earthquake | $84K |
Homes in Sioux City
Older homes and mobile homes usually take more damage in storms, floods and earthquakes. Ask about roof age, flood history and retrofits before you buy or rent.
Strongest tornadoes in Woodbury County
Common questions about Sioux City
Is Sioux City safe from natural disasters?
Sioux City is in Woodbury County, which FEMA's National Risk Index rates relatively moderate overall, about average for the US. The biggest hazards are inland flooding, tornado, cold wave. No place is free of risk, so check the flood map and insurance for any home you consider.
What natural disasters happen in Sioux City?
By expected yearly losses in Woodbury County, the top hazards are inland flooding (Moderate), tornado (High), cold wave (Moderate). Woodbury County has been part of 16 federal disaster or emergency declarations for natural events.
Does Sioux City get tornadoes?
Yes. NOAA records list 61 tornadoes in Woodbury County since 1950; the strongest was an F4 tornado on July 28, 1986. FEMA rates tornado risk in the county high.
Do I need flood insurance in Sioux City?
Standard home insurance does not cover floods. In Woodbury County, about 0.5% of homes have federal flood insurance, and FEMA rates inland flooding risk moderate. Check the FEMA flood map for your address and get a quote even outside a high-risk zone.