Based on NOAA Storm Events Database records from 1996 to 2025, these are the Maryland counties with the most recorded flood events. Baltimore County tops the list with 478 events. The data includes river floods, flash floods, coastal flooding, and hurricane-related flooding.
| Rank | County | Total Events | River Floods | Flash Floods |
|---|---|---|---|---|
| 1 | Baltimore County | 478 | 162 | 314 |
| 2 | Montgomery County | 428 | 186 | 242 |
| 3 | Frederick County | 287 | 195 | 92 |
| 4 | Harford County | 226 | 79 | 146 |
| 5 | Prince George's County | 216 | 99 | 117 |
| 6 | Anne Arundel County | 177 | 87 | 86 |
| 7 | Howard County | 161 | 71 | 90 |
| 8 | St. Mary's County | 159 | 85 | 72 |
| 9 | Carroll County | 143 | 74 | 69 |
| 10 | Allegany County | 109 | 48 | 61 |
| 11 | Washington County | 105 | 60 | 45 |
| 12 | Cecil County | 92 | 36 | 56 |
| 13 | Garrett County | 87 | 36 | 51 |
| 14 | Charles County | 83 | 43 | 39 |
| 15 | Baltimore city | 67 | 9 | 56 |
| 16 | Calvert County | 53 | 27 | 23 |
| 17 | Queen Anne's County | 42 | 10 | 32 |
| 18 | Worcester County | 38 | 14 | 24 |
| 19 | Dorchester County | 31 | 7 | 24 |
| 20 | Wicomico County | 30 | 9 | 21 |
| 21 | Caroline County | 27 | 8 | 19 |
| 22 | Talbot County | 26 | 3 | 23 |
| 23 | Kent County | 24 | 3 | 21 |
| 24 | Somerset County | 17 | 7 | 10 |
Source: NOAA Storm Events Database (1996–2025).
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