South And Gulf Coast of Mexico
South And Gulf Coast of Mexico Geography & Climate
Geography
This region spans the narrowest part of Mexico and the wettest, from the Gulf of Mexico across mountains to the Pacific.
The Isthmus of Tehuantepec
Mexico narrows here to about 200 kilometres between the two oceans, and the mountain chains drop low enough that Pacific air pours through. The result is the Tehuantepec wind — violent northerlies that funnel across the isthmus in winter, regularly exceeding 100 km/h, closing roads to high-sided vehicles and driving one of the largest wind-farm concentrations in Latin America.
Mountains and valleys
The Sierra Madre del Sur and the Sierra Madre de Oaxaca meet in a knot of steep, folded country cut by deep valleys — which is the reason for Oaxaca’s linguistic diversity, since communities a few kilometres apart were effectively isolated. The Chiapas highlands sit above 2,000 metres and are cool and pine-forested.
Pico de Orizaba
At 5,636 metres, the highest mountain in Mexico and the third highest in North America, a dormant volcano with glaciers, rising from a coastal plain only a hundred kilometres from the sea.
Rainforest
The Lacandon in eastern Chiapas is Mexico’s largest remaining tropical rainforest, much reduced, with the Montes Azules reserve protecting what is left. Tabasco is a low, hot, river-laced plain that floods.
Why Oaxaca has so many languages
The folded sierra here is exceptionally steep and the valleys narrow, and until recently a village two ridges away could be a day’s walk rather than an hour’s. Linguists treat Oaxaca as one of the world’s great centres of linguistic diversity for exactly this reason: Zapotec and Mixtec are not single languages but families of variants, some as different from one another as Spanish is from Italian, and the topography is why.
Seismic
Among the most earthquake-prone parts of Mexico; the 2017 Chiapas earthquake was the strongest recorded in the country in a century.
Climate Patterns
This is the wettest part of Mexico, and altitude divides it into sharply different zones.
The Gulf coast and Tabasco
Hot and humid year round, 28 to 34°C, with very high rainfall — parts of Tabasco and northern Chiapas receive over 3,000 millimetres a year, and some of the wettest places in Mexico are here. Flooding is routine; Villahermosa has been extensively inundated more than once.
The highlands
Oaxaca city at 1,550 metres has an almost perfect climate — 26 to 30°C by day and cool at night, dry from November to April. San Cristobal at 2,200 metres is considerably cooler, often 10°C or less at night, with mist and genuine cold in winter; visitors expecting tropical Mexico are caught out.
The wet season
May to October brings heavy afternoon rain across the region, with September the wettest month. Landslides close mountain roads in Chiapas and Oaxaca, and the jungle sites are humid and mosquito-ridden.
Nortes and hurricanes
The Gulf coast is hit by hurricanes from June to November, and by nortes — cold fronts driving strong northerlies — between October and March, which close the port at Veracruz and can drop temperatures sharply.
Packing for three climates
A typical itinerary here crosses climate zones that need different clothing on consecutive days. Palenque and the Gulf are hot and saturated; Oaxaca city is warm days and cool evenings; San Cristobal at 2,200 metres is genuinely cold at night and its older hotels often have no heating. Visitors regularly arrive with only tropical clothes and spend the Chiapas leg buying a wool jumper in the market, which is at least a good souvenir.
The isthmus wind
The Tehuantepec gap wind blows violently in winter, overturning lorries and making the isthmus one of the windiest places in the Americas.