City vs city
Harbor Island vs Port Royal, SC
Harbor Island currently scores 2 points higher overall than Port Royal, 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
Harbor Island: 47/100 · Port Royal: 45/100
Harbor Island is 2 points higher.
Flood
Harbor Island: 85/100 · Port Royal: 92/100
Port Royal is 7 points higher.
Harbor Island: FEMA NFHL flood zones: 13 features intersect this tile.
Port Royal: FEMA NFHL flood zones: 18 features intersect this tile.
Wind
Harbor Island: 49/100 · Port Royal: 45/100
Harbor Island is 4 points higher.
Harbor Island: Wind exposure derived from ingested design wind / climatology tiles.
Port Royal: Wind exposure derived from ingested design wind / climatology tiles.
Lightning
Harbor Island: 52/100 · Port Royal: 61/100
Port Royal is 9 points higher.
Harbor Island: Lightning exposure derived from ingested climatology tiles.
Port Royal: Lightning exposure derived from ingested climatology tiles.
Tornado
Harbor Island: 0/100 · Port Royal: 4/100
Port Royal is 4 points higher.
Harbor Island: Tornado risk derived from NOAA SPC historical reports.
Port Royal: Tornado risk derived from NOAA SPC historical reports.
Hail
Harbor Island: 4/100 · Port Royal: 24/100
Port Royal is 20 points higher.
Harbor Island: Hail risk derived from NOAA SPC historical reports.
Port Royal: Hail risk derived from NOAA SPC historical reports.
Storm surge
Harbor Island: 98/100 · Port Royal: 99/100
Port Royal is 1 points higher.
Harbor Island: Storm surge exposure derived from NOAA SLOSH MOM (AGL) data.
Port Royal: Storm surge exposure derived from NOAA SLOSH MOM (AGL) data.
Wildfire
Harbor Island: 16/100 · Port Royal: 10/100
Harbor Island is 6 points higher.
Harbor Island: Wildfire exposure derived from ingested fire potential tiles.
Port Royal: Wildfire exposure derived from ingested fire potential tiles.
Ingested air quality
Harbor Island: 24/100 · Port Royal: 21/100
Harbor Island is 3 points higher.
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.
Port Royal: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.