Maryland heat wave risk
Baltimore has the highest heat wave risk in Maryland, scoring 99.4 out of 100 — rated "Relatively High" by FEMA's National Risk Index. Recorded heat wave events across Maryland have decreased 52% over the past five years compared to the prior five-year period.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Baltimore | 99.4 | Relatively High | 31 |
| 2 | Baltimore County | 99.2 | Relatively High | 13 |
| 3 | Prince George's County | 97.8 | Relatively High | 28 |
| 4 | Montgomery County | 97 | Relatively High | 23 |
| 5 | Anne Arundel County | 93.2 | Relatively Moderate | 26 |
| 6 | Harford County | 90.9 | Relatively Moderate | 18 |
| 7 | Howard County | 89.3 | Relatively Moderate | 18 |
| 8 | Frederick County | 85.1 | Relatively Moderate | 12 |
| 9 | Talbot County | 81.7 | Relatively Moderate | 7 |
| 10 | Washington County | 79.2 | Relatively Moderate | 20 |
| 11 | Charles County | 78.8 | Relatively Moderate | 38 |
| 12 | Cecil County | 78.3 | Relatively Low | 6 |
| 13 | Carroll County | 75.2 | Relatively Low | 7 |
| 14 | Allegany County | 72.7 | Relatively Low | 10 |
| 15 | Calvert County | 68.5 | Relatively Low | 37 |
| 16 | St. Mary's County | 67.3 | Relatively Low | 44 |
| 17 | Wicomico County | 63.4 | Relatively Low | 1 |
| 18 | Dorchester County | 63 | Relatively Low | 1 |
| 19 | Queen Anne's County | 58 | Relatively Low | 7 |
| 20 | Caroline County | 57.7 | Relatively Low | 5 |
| 21 | Worcester County | 56.5 | Relatively Low | 1 |
| 22 | Kent County | 53.6 | Relatively Low | 6 |
| 23 | Somerset County | 37.5 | Very Low | 1 |
| 24 | Garrett County | 3.9 | Very Low | 0 |
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.
Heat Wave risk nationally:
Other hazard risks in Maryland:
Frequently asked questions
What is the highest heat wave risk county in Maryland?
Baltimore, MD has the highest heat wave risk in Maryland, with a FEMA National Risk Index score of 99.4 out of 100 (rated "Relatively High").
What causes heat wave risk in Maryland?
Heat is consistently the leading cause of weather-related mortality in the US, yet it remains underrepresented in federal disaster declarations relative to its actual impact. High scores reflect a combination of extreme temperature exposure, population vulnerability (elderly, outdoor workers), and limited access to cooling infrastructure.