Thresholds for Extreme Heat
Below are preliminary Heat Index (HI) thresholds for extreme heat*. These thresholds will be updated as more data become available.
| Region Number | Heat Index Threshold (°F) |
| 1 | 101 |
| 2 | 103 |
| 3 | 102 |
| 4 | 100 |
| 5 | 99 |
| 6 | 94 |
| 7 | 101 |
*Appropriate region groupings for each jurisdiction can be obtained from the map below. Counties are grouped based on similar HI thresholds.
