Final answer:
Mexico City has a subtropical highland climate due to its high elevation, with mild temperatures and a pronounced wet season, differing from the typically warmer, more tropical climate of Mexico's southern regions. The American Southwest has a hotter, more arid climate compared to Mexico City, with East Texas being an exception due to Gulf influences.
Step-by-step explanation:
The climate of Mexico City differs from that of the southern regions of Mexico primarily due to elevation and geographical location. Mexico City, situated at over 7,000 feet in elevation, experiences a subtropical highland climate, with mild temperatures year-round and a distinct wet season from June to October. In contrast, the south of Mexico, being closer to the equator and generally at lower elevations, has a more tropical climate with warmer temperatures and less temperature variation throughout the year.
In the American Southwest, states like Texas, New Mexico, and Arizona have an arid climate with hotter summers and mild winters due to their lower elevations compared to Mexico City. Eastern Texas, however, receives more rainfall influenced by the Gulf of Mexico, while western Texas, New Mexico, and Arizona are drier and more suited for cattle ranching with less agricultural activity due to water scarcity.
The southern hemisphere's climate, though comparable to the northern hemisphere's at similar latitudes, is moderated by the extensive ocean coverage. This creates a more temperate climate with less extreme seasonal temperature variations. In Mexico's northern arid regions, summers can be exceedingly hot with temperatures exceeding 110 °F, whereas winters can be very cold with snow in mountainous areas.