Oswego, Illinois: natural disaster risk
How exposed Oswego is to floods, storms and other hazards, from FEMA and NOAA records for Will County.
Oswego is a city of 36,375 people in Will County, Illinois. Parts of Oswego also reach into Kendall County. FEMA's National Risk Index rates Will County relatively high for natural hazards overall, higher than most of the US. The costliest hazards there are inland flooding, cold wave and tornado, with about $348 million in expected losses a year across the county. The weather service has logged 1,317 storm reports in the county since 1956, including 99 tornadoes and 164 floods. About 0.5% of homes in the county carry federal flood insurance.
Risk figures are for Will County, the county with most of the population Oswego 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 Oswego
Full Will 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.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- 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.
All hazards
| Hazard | Rating | A year |
|---|---|---|
| Inland flooding | $193M | |
| Cold wave | $72M | |
| Tornado | $63M | |
| Heat wave | $9M | |
| Earthquake | $7M | |
| Lightning | $2M | |
| Strong wind | $730K | |
| Winter weather | $617K | |
| Ice storm | $532K | |
| Hail | $498K | |
| Wildfire | $88K | |
| Drought | $72K |
Homes in Oswego
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 Will County
Common questions about Oswego
Is Oswego safe from natural disasters?
Oswego is in Will County, which FEMA's National Risk Index rates relatively high overall, higher than most of the US. The biggest hazards are inland flooding, cold wave, tornado. No place is free of risk, so check the flood map and insurance for any home you consider.
What natural disasters happen in Oswego?
By expected yearly losses in Will County, the top hazards are inland flooding (High), cold wave (Very High), tornado (Very High). Will County has been part of 17 federal disaster or emergency declarations for natural events.
Does Oswego get tornadoes?
Yes. NOAA records list 99 tornadoes in Will County since 1950; the strongest was an F5 tornado on August 28, 1990. FEMA rates tornado risk in the county very high.
Do I need flood insurance in Oswego?
Standard home insurance does not cover floods. In Will County, about 0.5% of homes have federal flood insurance, and FEMA rates inland flooding risk high. Check the FEMA flood map for your address and get a quote even outside a high-risk zone.