Maine inland flooding risk
Penobscot County has the highest inland flooding risk in Maine, scoring 83 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index. Recorded inland flooding events across Maine have increased 171% over the past five years compared to the prior five-year period.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Penobscot County | 83 | Relatively Moderate | 18 |
| 2 | York County | 81.3 | Relatively Moderate | 12 |
| 3 | Kennebec County | 80.1 | Relatively Moderate | 35 |
| 4 | Aroostook County | 76.1 | Relatively Moderate | 35 |
| 5 | Oxford County | 73.3 | Relatively Moderate | 94 |
| 6 | Cumberland County | 72.3 | Relatively Low | 31 |
| 7 | Somerset County | 61.8 | Relatively Low | 52 |
| 8 | Androscoggin County | 61.6 | Relatively Low | 35 |
| 9 | Franklin County | 53 | Relatively Low | 53 |
| 10 | Hancock County | 45.2 | Relatively Low | 6 |
| 11 | Washington County | 41.4 | Relatively Low | 7 |
| 12 | Waldo County | 39.6 | Relatively Low | 8 |
| 13 | Piscataquis County | 35.2 | Relatively Low | 20 |
| 14 | Lincoln County | 28.8 | Very Low | 5 |
| 15 | Sagadahoc County | 26.1 | Very Low | 2 |
| 16 | Knox County | 21.4 | Very Low | 9 |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.
Inland Flooding risk nationally:
Other hazard risks in Maine:
Frequently asked questions
What is the highest inland flooding risk county in Maine?
Penobscot County, ME has the highest inland flooding risk in Maine, with a FEMA National Risk Index score of 83 out of 100 (rated "Relatively Moderate").
What causes inland flooding risk in Maine?
Inland flooding covers riverine and surface (pluvial) flooding — the most common and costly natural disaster type in the US. High scores appear across river floodplains in the Midwest, South, and Mid-Atlantic, where legacy development in flood-prone areas and aging stormwater infrastructure concentrate risk.