Mexico is highly susceptible to tropical cyclones, possessing long coastlines facing two of the world’s most active regions for these powerful weather systems. A hurricane is a powerful, rotating storm that forms over warm ocean waters, characterized by strong winds and a low-pressure center. It is classified as a hurricane when sustained wind speeds reach 74 miles per hour or greater in the North Atlantic or Eastern Pacific basins. Mexico’s geographical position puts it squarely in the path of storms originating from both the Pacific and Atlantic sides.
Mexico’s Exposure to Two Major Basins
Mexico possesses a unique vulnerability due to its extensive coastline bordering both the Eastern Pacific Hurricane Basin and the Atlantic Hurricane Basin (including the Gulf of Mexico and the Caribbean Sea). The Pacific coast, which is the longest in Mexico, is frequently affected by storms that tend to track northwestward, often paralleling the coastline.
States along the Pacific side, such as Baja California Sur, Sinaloa, Oaxaca, and Michoacán, are the most common targets for Pacific hurricanes. Historically, the Eastern Pacific basin generates a higher number of named storms annually compared to the Atlantic basin. However, many of these storms dissipate over cooler waters or move away from the Mexican mainland, meaning the number of direct landfalls is often lower than the total number of storms formed.
In contrast, the Atlantic basin impacts the eastern coast, including the Yucatán Peninsula and the Gulf coast states of Veracruz and Tamaulipas. The Atlantic side, particularly the low-lying Yucatán Peninsula, experiences a higher frequency of hurricane landfalls per unit of coastline length. The Atlantic basin has also historically produced a greater number of the most intense, Category 5 hurricanes making landfall on the Gulf and Caribbean coasts.
Pacific storms frequently exhibit rapid intensification over warm offshore waters, followed by rapid weakening just before or after landfall. This makes forecasting their precise strength a challenge for coastal communities. The difference in ocean depth and currents between the two coasts contributes to the varied behavior and intensity of the storms that ultimately affect Mexico.
Defining the Hurricane Seasonality
The hurricane season is the defined period when ocean temperatures and atmospheric conditions are most conducive to tropical cyclone formation. The official dates differ slightly between the two basins affecting Mexico. The Atlantic Hurricane Season, which includes the Gulf of Mexico and the Caribbean, officially runs from June 1st to November 30th.
The Eastern Pacific Hurricane Season begins slightly earlier, starting on May 15th and concluding on November 30th. While tropical systems can occasionally form outside of these established windows, the vast majority of activity occurs within this six-month period. These dates mark the time when sea surface temperatures consistently exceed the 79°F (26°C) threshold needed to fuel the storms.
Activity usually builds throughout the summer, with the highest risk period occurring in the late summer and early autumn. For the Atlantic side, the season’s peak is in September, with the most intense activity observed from mid-August through mid-October. The Eastern Pacific also sees its climatological peak in late August and September.
September is historically the month of maximum hurricane landfalls on both the Pacific and Atlantic coasts of Mexico. The predictable annual warming of the oceans dictates this seasonal pattern, making preparedness during this time particularly important.
Understanding Storm Intensity and Impact
A hurricane’s intensity is measured using the Saffir-Simpson Hurricane Wind Scale, which classifies storms from Category 1 to 5 based solely on maximum sustained wind speed. A Category 1 hurricane (74 to 95 mph) causes some damage to structures and widespread power outages. By contrast, a Category 3 storm (111 to 129 mph) is considered a major hurricane capable of causing devastating damage, including major roof and wall failures, with power and water likely unavailable for weeks.
The highest classification, Category 5, involves catastrophic damage from winds exceeding 157 mph, which can destroy a high percentage of framed homes and render affected areas uninhabitable for extended periods. Beyond wind, the primary threats from hurricanes are storm surge, heavy rainfall, and inland flooding. Storm surge, which is the abnormal rise of water generated by the storm above the predicted astronomical tide, is often responsible for the greatest destruction and loss of life near the coast.
Low-lying coastal areas, such as the Yucatán Peninsula, are especially vulnerable to the devastating effects of storm surge. The extreme amount of heavy rainfall associated with hurricanes can also lead to widespread inland flooding and dangerous mudslides, even from weaker storms. States in the southern Pacific, like Michoacán and Guerrero, frequently experience destructive flooding and landslides, even when the storm makes landfall further away or only passes offshore.