City vs city
Marthasville vs Union, MO
Union currently scores 7 points higher overall than Marthasville, with the largest gap in tornado.
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
Marthasville: 40/100 · Union: 47/100
Union is 7 points higher.
Flood
Marthasville: 57/100 · Union: 50/100
Marthasville is 7 points higher.
Marthasville: FEMA NFHL flood zones: 4 features intersect this tile.
Union: FEMA NFHL flood zones: 14 features intersect this tile.
Wind
Marthasville: 16/100 · Union: 16/100
No gap.
Marthasville: Wind exposure derived from ingested design wind / climatology tiles.
Union: Wind exposure derived from ingested design wind / climatology tiles.
Lightning
Marthasville: 50/100 · Union: 51/100
Union is 1 points higher.
Marthasville: Lightning exposure derived from ingested climatology tiles.
Union: Lightning exposure derived from ingested climatology tiles.
Tornado
Marthasville: 0/100 · Union: 42/100
Union is 42 points higher.
Marthasville: Tornado risk derived from NOAA SPC historical reports.
Union: Tornado risk derived from NOAA SPC historical reports.
Hail
Marthasville: 62/100 · Union: 100/100
Union is 38 points higher.
Marthasville: Hail risk derived from NOAA SPC historical reports.
Union: Hail risk derived from NOAA SPC historical reports.
Storm surge
Marthasville: Unavailable · Union: Unavailable
A score difference cannot be calculated without both sources.
Marthasville: Storm surge model is not available for this location yet.
Union: Storm surge model is not available for this location yet.
Wildfire
Marthasville: 27/100 · Union: 46/100
Union is 19 points higher.
Marthasville: Wildfire exposure derived from ingested fire potential tiles.
Union: Wildfire exposure derived from ingested fire potential tiles.
Ingested air quality
Marthasville: 27/100 · Union: 27/100
No gap.
Marthasville: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.
Union: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.