City vs city
Alton vs Sioux City, IA
Sioux City currently scores 7 points higher overall than Alton, with the largest gap in flood.
Use this comparison for relocation decisions, insurance shopping, and hazard-prioritized mitigation planning.
Hazard breakdown
Scores describe each city’s reference grid tile, not every property. A missing model is unavailable, not zero risk. Air quality uses an ingested EPA AirNow snapshot and may not reflect current conditions; other factors describe baseline exposure. The overall score blends different hazards and is not a probability of damage. Read the scoring methodology and sources.
Overall
Alton: 32/100 · Sioux City: 39/100
Sioux City is 7 points higher.
Flood
Alton: 59/100 · Sioux City: 4/100
Alton is 55 points higher.
Alton: FEMA NFHL flood zones: 9 features intersect this tile.
Sioux City: FEMA NFHL flood zones: 2 features intersect this tile.
Wind
Alton: 20/100 · Sioux City: 20/100
No gap.
Alton: Wind exposure derived from ingested design wind / climatology tiles.
Sioux City: Wind exposure derived from ingested design wind / climatology tiles.
Lightning
Alton: 51/100 · Sioux City: 52/100
Sioux City is 1 points higher.
Alton: Lightning exposure derived from ingested climatology tiles.
Sioux City: Lightning exposure derived from ingested climatology tiles.
Tornado
Alton: 8/100 · Sioux City: 38/100
Sioux City is 30 points higher.
Alton: Tornado risk derived from NOAA SPC historical reports.
Sioux City: Tornado risk derived from NOAA SPC historical reports.
Hail
Alton: 34/100 · Sioux City: 86/100
Sioux City is 52 points higher.
Alton: Hail risk derived from NOAA SPC historical reports.
Sioux City: Hail risk derived from NOAA SPC historical reports.
Storm surge
Alton: Unavailable · Sioux City: Unavailable
A score difference cannot be calculated without both sources.
Alton: Storm surge model is not available for this location yet.
Sioux City: Storm surge model is not available for this location yet.
Wildfire
Alton: 29/100 · Sioux City: 48/100
Sioux City is 19 points higher.
Alton: Wildfire exposure derived from ingested fire potential tiles.
Sioux City: Wildfire exposure derived from ingested fire potential tiles.
Ingested air quality
Alton: 24/100 · Sioux City: 26/100
Sioux City is 2 points higher.
Alton: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.
Sioux City: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.