All hurricanes are dangerous, but some more so than others. The way storm surge, wind, and other factors combine determines the hurricane’s destructive power. To make comparisons easier-and to make the predicted hazards of approaching hurricanes clearer to emergency forces-National Oceanic and Atmospheric Administration’s hurricane forecasters use a disaster-potential scale which assigns storms to five categories.
Category 1 is a minimum hurricane; category 5 is the worst case. The criteria for each category in the table shown below:
| Category | Central Pressure | Maximum Winds | Storm Surge |
|---|---|---|---|
| Tropical Depression | 38 mph / 34 kts or less | 4-5 ft. | |
| Tropical Storm | > 980 mb or 28.94 in | 39-73 mph or 34-63 kts | 4-5 ft. |
| 1 – Minimal | < 980 mb or 28.94 in | 74-95 mph or 64-83 kts | 4-5 ft. |
| 2 – Moderate | 965-979 mb or 28.50-28.91 in | 96-110 mph or 65-96 kts | 6-8 ft. |
| 3 – Extensive | 945-964 mb or 27.91-28.47 in | 111-130 mph or 97-113 kts | 9-12ft. |
| 4 – Extreme | 920-944 mb or 27.17-27.88 in | 131-155 mph or 114-135 kts | 13-18 ft. |
| >5 – Catastrophic | < 920 mb or 27.17 in | > 155 mph or 135 kts | > 18 ft. |
* – The Saffir-Simpson Hurricane Scale is based on Windspeed alone, the pressures are only included as a general reference and may not always apply
