City vs city
Portsmouth vs Rochester, NH
Portsmouth currently scores 9 points higher overall than Rochester, 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
Portsmouth: 41/100 · Rochester: 32/100
Portsmouth is 9 points higher.
Flood
Portsmouth: 73/100 · Rochester: 64/100
Portsmouth is 9 points higher.
Portsmouth: FEMA NFHL flood zones: 12 features intersect this tile.
Rochester: FEMA NFHL flood zones: 12 features intersect this tile.
Wind
Portsmouth: 23/100 · Rochester: 21/100
Portsmouth is 2 points higher.
Portsmouth: Wind exposure derived from ingested design wind / climatology tiles.
Rochester: Wind exposure derived from ingested design wind / climatology tiles.
Lightning
Portsmouth: 6/100 · Rochester: 7/100
Rochester is 1 points higher.
Portsmouth: Lightning exposure derived from ingested climatology tiles.
Rochester: Lightning exposure derived from ingested climatology tiles.
Tornado
Portsmouth: 0/100 · Rochester: 15/100
Rochester is 15 points higher.
Portsmouth: Tornado risk derived from NOAA SPC historical reports.
Rochester: Tornado risk derived from NOAA SPC historical reports.
Hail
Portsmouth: 22/100 · Rochester: 61/100
Rochester is 39 points higher.
Portsmouth: Hail risk derived from NOAA SPC historical reports.
Rochester: Hail risk derived from NOAA SPC historical reports.
Storm surge
Portsmouth: 98/100 · Rochester: Unavailable
A score difference cannot be calculated without both sources.
Portsmouth: Storm surge exposure derived from NOAA SLOSH MOM (AGL) data.
Rochester: Storm surge model is not available for this location yet.
Wildfire
Portsmouth: 43/100 · Rochester: 36/100
Portsmouth is 7 points higher.
Portsmouth: Wildfire exposure derived from ingested fire potential tiles.
Rochester: Wildfire exposure derived from ingested fire potential tiles.
Ingested air quality
Portsmouth: 23/100 · Rochester: 23/100
No gap.
Portsmouth: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.
Rochester: Air quality score derived from the latest ingested EPA AirNow AQI grid; may not reflect current conditions. See methodology for the recorded ingest date.