City vs city
Charleston vs Harbor Island, SC
Charleston currently scores 14 points higher overall than Harbor Island, with the largest gap in hail.
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
Charleston: 61/100 · Harbor Island: 47/100
Charleston is 14 points higher.
Flood
Charleston: 89/100 · Harbor Island: 85/100
Charleston is 4 points higher.
Charleston: FEMA NFHL flood zones: 33 features intersect this tile.
Harbor Island: FEMA NFHL flood zones: 13 features intersect this tile.
Wind
Charleston: 52/100 · Harbor Island: 49/100
Charleston is 3 points higher.
Charleston: Wind exposure derived from ingested design wind / climatology tiles.
Harbor Island: Wind exposure derived from ingested design wind / climatology tiles.
Lightning
Charleston: 45/100 · Harbor Island: 52/100
Harbor Island is 7 points higher.
Charleston: Lightning exposure derived from ingested climatology tiles.
Harbor Island: Lightning exposure derived from ingested climatology tiles.
Tornado
Charleston: 65/100 · Harbor Island: 0/100
Charleston is 65 points higher.
Charleston: Tornado risk derived from NOAA SPC historical reports.
Harbor Island: Tornado risk derived from NOAA SPC historical reports.
Hail
Charleston: 100/100 · Harbor Island: 4/100
Charleston is 96 points higher.
Charleston: Hail risk derived from NOAA SPC historical reports.
Harbor Island: Hail risk derived from NOAA SPC historical reports.
Storm surge
Charleston: 98/100 · Harbor Island: 98/100
No gap.
Charleston: Storm surge exposure derived from NOAA SLOSH MOM (AGL) data.
Harbor Island: Storm surge exposure derived from NOAA SLOSH MOM (AGL) data.
Wildfire
Charleston: 15/100 · Harbor Island: 16/100
Harbor Island is 1 points higher.
Charleston: Wildfire exposure derived from ingested fire potential tiles.
Harbor Island: Wildfire exposure derived from ingested fire potential tiles.
Ingested air quality
Charleston: 26/100 · Harbor Island: 24/100
Charleston is 2 points higher.
Charleston: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.
Harbor Island: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.