States of Mexico
Mexico and its states can be divided into the following regions:

Baja California Peninsula
Located in the Northwest region, the Baja California Peninsula borders the United States on the north, and lies east of the Pacific Ocean and west of the Sea of Cortez. The peninsula has an ideal climate, with sunny days throughout most of the year and average temperatures ranging from 15° C (59° F) in the winter and 30° C (86° F) during the summer. Its territory, which spans about 1,300 kilometers (806 miles) from north to south, is divided into two states: Baja California and Baja California Sur.

Northern Mexico
The deserts and dunes of the north extend across the states of Sonora, Chihuahua, Coahuila, Nuevo Leon, Tamaulipas, Durango and Zacatecas, where maximum summer temperatures range between 32ºC and 36ºC (90ºF and 97ºF) and winter lows drop below 0ºC (32ºF). The western and eastern mountain ranges of the Sierra Madre stretch across the region as well.

The Pacific Coast
Located in western Mexico, the Pacific coast region stretches across 1,700 kilometers (1,054 miles) of beaches, mountains and valleys, spanning the states of Sinaloa, Nayarit, Jalisco, Colima, Michoacan, Guerrero and Oaxaca. The climate is hot and tropical (temperatures range from 15°C, or 59°F, to 32°C, or 90°F) along the coast, while the zone that makes up part of the Sierra Madre del Sur mountain range gets much cooler.

Central Mexico
Central Mexico is one of the country’s richest regions in culture and natural beauty. Its territory extends from the outer limits of a high plateau in the north to the edge of the Sierra Madre range in the south. Temperatures are moderate throughout most of the year, ranging from 3ºC (26ºF) in the winter to 30ºC (86ºF) in the summer. The climate can vary considerably depending on the geographic zone. In this region you can appreciate archaeological zones, colonial architecture, picturesque towns known for their fairs, convents and haciendas, as well as enjoy the beauty of the nature reserves. All of this can be found in the states of San Luis Potosi, Aguascalientes, Guanajuato, Queretaro, Hidalgo, Mexico, Tlaxcala, Puebla, Morelos and in Mexico City.
Southern Mexico and the Gulf of Mexico

Southern Mexico
This region, which boasts some of the most amazing and diverse ecosystems on the planet, lies between two major bodies of water: the Gulf of Mexico and the Pacific Ocean. Rich in natural resources, culture and tradition, the states of Veracruz, Tabasco and Chiapas have tropical and semi-tropical climates (temperatures exceed 25°C, or 77°F).

The Yucantan Peninsula
The Yucatan Peninsula, located in southeastern Mexico between the Gulf of Mexico and the Caribbean Sea, has a year-round hot and humid climate, which is ideal for enjoying its Beach Resorts and natural paradises. The region, which comprises the states of Campeche, Yucatan and Quintana Roo, is well known for its numerous Mayan archeological sites. Many of the ancient traditions of the Mayas persist, for example, many women wear a traditional blouse called a huipil, and some homes are still built with straw rooftops. There are also the regional henequen haciendas, many of which have been converted into posh hotels. And then there are the blue waters of the Caribbean Sea that wash onto white-sand beaches, where you will find world-class hotels.
Source: Mexico Tourism Board