For residents and visitors of Maine, the concept of a hurricane often feels like a distant worry, reserved for states much further south. Maine’s position as the northernmost point on the East Coast contributes to a common perception of immunity from powerful tropical systems. While the state is within the Atlantic hurricane basin, determining if a hurricane truly hits Maine requires examining meteorological definitions and historical events. The nature of the threat changes significantly by the time these storms approach New England.
The Official Answer Hurricane Landfalls in Maine
To determine if a hurricane officially “hits” a state, meteorologists rely on the definition of a hurricane landfall. This occurs when the center of the storm’s eye crosses the coastline while maintaining sustained wind speeds of 74 miles per hour or greater. Under this strict criterion, Maine has experienced very few true hurricane landfalls throughout recorded history.
The last storm widely cited to make landfall in Maine while maintaining hurricane strength was Hurricane Gerda in 1969, which struck Downeast Maine as a minimal Category 1 storm. Another exception was Hurricane Edna in 1954, also a Category 1 landfall. Many destructive storms that impacted Maine, such as Hurricane Bob in 1991, were downgraded to a tropical storm by the time their center crossed the coast, even if they produced hurricane-force gusts. The historical record shows that the return period for a genuine hurricane strength landfall in coastal Maine is upwards of 300 years.
Why Maine is Protected
Two primary factors strip tropical cyclones of their intensity before they can make landfall on the Maine coast. The first involves the influence of cold ocean water in the region. Hurricanes require sea surface temperatures of at least 80 degrees Fahrenheit to maintain their strength, drawing energy from warm, moist air.
The Gulf of Maine is influenced by the cold Labrador Current, keeping sea surface temperatures typically in the mid-60s to low 70s. Once a tropical system moves over this colder water, it rapidly loses the fuel necessary to sustain its powerful wind speeds and organized structure. This causes the storm to quickly weaken or transition into a different type of weather system.
The second factor is the typical steering pattern at Maine’s high latitude. As storms move northward up the East Coast, they are often caught by the prevailing mid-latitude westerlies, which push weather systems eastward. This pattern causes many hurricanes to recurve and accelerate out into the open North Atlantic Ocean before reaching the New England coastline. High-pressure systems also influence the track, often pushing storms away from the coast and forcing them to transition into non-tropical systems.
The Common Threat Post-Tropical Impacts
While direct hurricane landfall is rare, Maine is highly vulnerable to the impacts of systems downgraded to tropical storms or post-tropical remnants. These systems still carry immense tropical moisture, often bringing heavy rainfall that is the state’s most significant hazard. The rainfall leads to widespread inland flooding, particularly along rivers and low-lying areas, causing substantial damage far from the coast.
Past events illustrate this danger; for instance, the remnants of Hurricane Floyd in 1999 dropped over a foot of rain in some parts of the state, resulting in major river flooding. Even when the storm center remains offshore, the large wind field of a weakening system can still produce significant winds, leading to downed trees and extensive power outages. Coastal areas are also susceptible to dangerous surf, beach erosion, and storm surge, even from systems that have lost their tropical characteristics.