New Jersey heat wave risk
Essex County has the highest heat wave risk in New Jersey, scoring 99 out of 100 — rated "Relatively High" by FEMA's National Risk Index. Recorded heat wave events across New Jersey have increased 610% over the past five years compared to the prior five-year period.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Essex County | 99 | Relatively High | 5 |
| 2 | Hudson County | 98.8 | Relatively High | 0 |
| 3 | Monmouth County | 98.6 | Relatively High | 17 |
| 4 | Camden County | 97 | Relatively High | 13 |
| 5 | Bergen County | 96.8 | Relatively High | 0 |
| 6 | Middlesex County | 96.5 | Relatively Moderate | 18 |
| 7 | Union County | 96.2 | Relatively Moderate | 3 |
| 8 | Passaic County | 96.1 | Relatively Moderate | 0 |
| 9 | Mercer County | 95.8 | Relatively Moderate | 10 |
| 10 | Ocean County | 95.7 | Relatively Moderate | 17 |
| 11 | Burlington County | 93.8 | Relatively Moderate | 13 |
| 12 | Gloucester County | 93.6 | Relatively Moderate | 13 |
| 13 | Cape May County | 92.4 | Relatively Moderate | 1 |
| 14 | Morris County | 89.2 | Relatively Moderate | 12 |
| 15 | Atlantic County | 89.1 | Relatively Moderate | 0 |
| 16 | Cumberland County | 88.2 | Relatively Moderate | 2 |
| 17 | Somerset County | 88 | Relatively Moderate | 19 |
| 18 | Salem County | 76.5 | Relatively Low | 4 |
| 19 | Warren County | 72.2 | Relatively Low | 3 |
| 20 | Hunterdon County | 72.1 | Relatively Low | 10 |
| 21 | Sussex County | 59.8 | Relatively Low | 2 |
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 New Jersey:
Frequently asked questions
What is the highest heat wave risk county in New Jersey?
Essex County, NJ has the highest heat wave risk in New Jersey, with a FEMA National Risk Index score of 99 out of 100 (rated "Relatively High").
What causes heat wave risk in New Jersey?
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.