Which county in New Hampshire has the lowest flood risk?

Hillsborough has the lowest flood risk in New Hampshire, at 52.9.

What is the flood risk in Hillsborough?

Hillsborough is ranked #1 in New Hampshire for flood risk, at 52.9.

What are the top counties in New Hampshire for flood risk?

Hillsborough (52.9), then Merrimack (59.0), and Strafford (60.4). The full top 10 is in the table on this page.

How is this flood risk ranking calculated?

Counties in New Hampshire are ranked by flood risk (FEMA National Risk Index, FEMA NRI v1.20), lowest first. Values describe the county, not an individual property. Source vintage is shown on the page.

How does New Hampshire compare to the rest of the US for flood risk?

This list is New Hampshire only. See the national ranking of the lowest counties for flood risk at hearthmap.app/best/lowest-flood-risk.

Lowest Flood Risk Counties in New Hampshire (2026)

Lowest counties for flood risk in New Hampshire

Top 10 of 10 counties with data.

Ranked by flood risk (FEMA National Risk Index, FEMA NRI v1.20), lowest first.

Lowest counties for flood risk in New Hampshire

Rank	County	Value
01	Hillsborough52.9 County page
02	Merrimack59.0 County page
03	Strafford60.4 County page
04	Rockingham61.9 County page
05	Belknap64.9 County page
06	Cheshire72.4 County page
07	Sullivan72.6 County page
08	Carroll77.1 County page
09	Coos83.5 County page
10	Grafton86.9 County page

How this ranking works

This page ranks New Hampshire counties by flood risk, sorted so the lowest places appear first. Click any county to see its housing, schools, crime, and demographics in detail.

For flood risk, a lower value is generally more favorable, so the top of the list is the lowest. Want to weigh flood risk against schools, taxes, commute, and more at once? Use the live map to build a custom match.

Data comes from public sources. Source attribution and the exact data vintage are shown above and on the full map of flood risk.

Frequently asked questions

Which county in New Hampshire has the lowest flood risk?: Hillsborough has the lowest flood risk in New Hampshire, at 52.9.
What is the flood risk in Hillsborough?: Hillsborough is ranked #1 in New Hampshire for flood risk, at 52.9.
What are the top counties in New Hampshire for flood risk?: Hillsborough (52.9), then Merrimack (59.0), and Strafford (60.4). The full top 10 is in the table on this page.
How is this flood risk ranking calculated?: Counties in New Hampshire are ranked by flood risk (FEMA National Risk Index, FEMA NRI v1.20), lowest first. Values describe the county, not an individual property. Source vintage is shown on the page.
How does New Hampshire compare to the rest of the US for flood risk?: This list is New Hampshire only. See the national ranking of the lowest counties for flood risk at hearthmap.app/best/lowest-flood-risk.