The climate of Mexico is very varied. The Tropic of Cancer effectively divides the country into temperate and tropical zones. Land that is north of the twenty-fourth parallel experiences lower temperatures during the winter months. South of the twenty-fourth parallel, temperatures are fairly consistent all year round and vary solely as a function of elevation. The north of the country usually receives less precipitation than the south.
By region
Areas south of the twentieth-fourth parallel with elevations up to , have a yearly median temperature between. Temperatures here remain high throughout the year, with only a difference between winter and summer median temperatures. Although low-lying areas north of the twenty-fourth parallel are hot and humid during the summer, they generally have lower yearly temperature averages because of more moderate conditions during the winter. . soon after its birth in 1943 in a Mexican cornfield. During its brief nine-year lifespan, it built a 410-meter-high cone with extensive lava fields around the base of the cone. Most of the 2 km3 of eruptive products were produced in the first few years. Cinder cones such as this one are commonly formed by one eruption. Each subsequent eruption in the same area forms its own cinder cone. Between, one encounters yearly average temperatures between. Towns and cities at this elevation south of the twenty-fourth parallel have relatively constant, pleasant temperatures throughout the year, whereas more northerly locations experience sizeable seasonal variations. Above, temperatures drop as low as an average yearly range between in the Cordillera Neovolcánica. At, Mexico City has a yearly median temperature of with pleasant summers and mild winters. Average daily highs and lows for May, the warmest month, are, and average daily highs and lows for January, the coldest month, are. Rainfall varies widely both by location and season. Arid or semiarid conditions are encountered in the Baja California Peninsula, the northwestern state of Sonora, the northern altiplano, and also significant portions of the southern altiplano. Rainfall in these regions averages between per year, although even less in some areas, particularly in the state of Baja California. Average rainfall totals are between in most of the major populated areas of the southern altiplano, including Mexico City and Guadalajara. Low-lying areas along the Gulf of Mexico receive in excess of of rainfall in an average year, with the wettest region being the southeastern state of Tabasco, which typically receives approximately of rainfall on an annual basis. Parts of the northern altiplano, highlands and high peaks in the Sierra Madres receive yearly snowfall. Citlaltépetl, Popocatépetl and, Iztaccíhuatl continue to support glaciers, the largest of which is the Gran Glaciar Norte. Mexico has pronounced wet and dry seasons. Most of the country experiences a rainy season from June to mid-October and significantly less rain during the remainder of the year. February and July generally are the driest and wettest months, respectively. Mexico City, for example, receives an average of only of rain during February but more than in July. Coastal areas, especially those along the Gulf of Mexico, experience the largest amounts of rain in September. Tabasco typically records more than of rain during that month. A portion of northwestern Baja California has a Mediterranean climate influenced by the California Current, with a rainy season that occurs in winter and coastal regions receiving considerable fog. Another area of the Mediterranean climate as a result of elevation occurs in the interior of Sonora. Mexico lies squarely within the hurricane belt, and all regions of both coasts are susceptible to these storms from June through November. Hurricanes on the Pacific coast are often less violent than those affecting Mexico's eastern coastline. Several hurricanes per year strike the Caribbean and Gulf of Mexico coastline, however, and these storms bring high winds, heavy rain, extensive damage, and occasional loss of life. Hurricane Gilbert passed directly over Cancún in September 1988, with winds in excess of, producing major damage to hotels in the resort area. It then struck northeast Mexico, where flooding from the heavy rain killed dozens in the Monterrey area and caused extensive damage to livestock and vegetable crops.
