Here we go again, Houston. The 2024 hurricane season and Hurricane Beryl certainly left their mark. Despite only being classified as Category 1, Beryl still managed to pack a punch, causing days-long power outages for 2.26 million Houstonians, severe flooding, and heavy property damage.

With all the talk of categories and how reflective they are of impact, you might be wondering: Why do storms have these rankings in the first place? Let’s dive into the history, purpose, and specifics of hurricane categories, and shed some light on how they came to be.

Where do hurricane categories come from?

The system we rely on today is the Saffir-Simpson Hurricane Wind Scale (SSHWS). It was developed in 1971 by engineer Herbert Saffir and meteorologist Robert Simpson. Recognizing the need for a clear and concise way to communicate a hurricane’s potential for destruction, they devised a five-tier scale based on a storm’s sustained wind speed. This simple metric offered a quick and easy way for coastal communities to grasp the possible severity of an incoming hurricane.

At that time, Saffir was working on a report for the United Nations about the damage potential of windstorms. To address the lack of a simple way to describe the likely damage and impact of a hurricane, he created a scale based on wind speed and shared it with Simpson, who was the director of the National Hurricane Center. Simpson expanded the scale to include the effects of storm surges and floodings. And that’s how the SSHWS—and as a result, hurricane categories—were born.

How do hurricane categories work?

The SSHWS assigns hurricanes a category (one to five) based on their sustained wind speeds. Here’s a breakdown of each category and what it typically means.

● Category 1: Winds range from 74–95mph. It can cause damage to poorly constructed signs, unanchored mobile homes, trees, power lines, etc. Loose outdoor items become dangerous projectiles, and power outages are likely. While not catastrophic, it can still disrupt daily life.

● Category 2: With wind speed ranging from 96–110mph, there is a risk of injuries and death due to flying and falling items. It also brings significant damage to roofs, windows, and doors, and considerable damage to trees and plants. Near-total power loss is expected, with outages potentially lasting several days to weeks.

● Category 3: This is where we start getting into major hurricane territory. Packing sustained winds of 111–129mph, it brings significant structural damage to residences and roofs. Flooding from storm surges and inland rainfall could become a serious threat. There is also the potential that evacuations in low-lying areas would be necessary and power outages could last for weeks.

● Category 4: Hurricanes in this category are extremely dangerous, with sustained winds ranging from 130–156mph. They cause disastrous roof failures and wall collapses. Even well-built homes could experience significant damage. Power outages are expected to be complete and could take months to restore. Evacuations from coastal areas and low or flat inland areas become crucial.

● Category 5: The most intense on the scale, with sustained winds of at least 157mph. It causes catastrophic damage, with a high potential for complete roof failure and structural collapse. Most, if not all, homes can be destroyed. Power outages are expected to be total and could take a long time to fully restore. Evacuations from all areas become essential.

It is important to remember that the SSHWS is just one piece of the puzzle. While wind speed is a crucial factor, surges, rainfall, and storm size can greatly impact overall damage. A slow-moving storm, even at a lower category, can dump a tremendous amount of rain in a short period of time, leading to devastating floods—like we saw during Harvey, for example.

Houston’s brushes with hurricanes

The Bayou City has a long history of hurricanes. While the SSHWS is a valuable tool to understand the impact of these storms, it doesn’t always tell the complete picture—as we saw during Beryl, a Category 1 that resulted in the most power outages in CenterPoint history.

Here’s a look at some notable hurricanes that have struck the Houston area in the last century.