The average temperature in Cancún is 27° C (80° F) with more than 240 days of sunshine, and rain is rare, with late August through early October being the rainy season. The beaches are almost 100 percent limestone; the porous quality of the limestone makes for cool sand even under the intense tropical sun. Cancún is divided into two parts: The narrow 23-kilometer-long (14-mile) island section (Cancún Island) is lined with modern beachfront hotels surrounded by the Bahía de Mujeres (Bay of Women), the Caribbean Sea, and the Nichupte and Bojorquez lagoons. The mainland downtown commercial section (Cancún City), connected to the island by two bridges, has broad avenues lined with whitewashed shops, restaurants, and hotels.

In the early 1950s Cancún was an almost unpopulated and undeveloped island just off the Caribbean Sea coast of the Yucatán peninsula, home to three caretakers of a coconut plantation and small Pre-Columbian ruins of the Maya civilization. The government of Mexico decided to develop a tourist resort on Cancún, which was originally financed by a USD $27 million loan from the International Development Bank. A causeway was built to link Cancún to the mainland, and an international airport was built, along with what was at first a model city for workers, complete with housing, schools and medical facilities. On the opposite side of the island from the Caribbean Sea is Nichupte Lagoon, which is used for boat and snorkelling tours of the area.

Development of Cancún started in 1970 and grew rapidly in the 1980s. Unfortunately, the original very sensible master plan was repeatedly modified and, on the mainland, often ignored. According to long-time resident Jules Siegel (author of the "Cancún User's Guide" and translator of Fernando Martí's "Cancún, Fantasy of Bankers"), municipal authorities have struggled to provide public services for the constant influx of people, as well as to control squatters and irregular developments, which now occupy an estimated ten to fifteen percent of the mainland area on the fringes of the city, he says.

Despite initial skepticism that forced the Mexican government to finance the first eight hotels, Cancún soon attracted investors from all over the world, but approximately 70% of the Hotel Zone properties are owned by Mexicans, many of them local residents, Siegel says. The figure is close to 100% for the mainland. Some observers believe that the resort is foreign-owned because they are confused by the hotel operating companies, which are international companies that supply administration and marketing services. They do not usually own the hotels themselves. Even outlets of restaurant chains such as McDonald's and Domino's Pizza are Mexican-owned.

The city has grown rapidly over the past thirty years to become a city of approximately 500,000 residents, covering the former island and the nearby mainland. There are actually very few true 'cancunenses' (people originally from Cancún) because of the rate at which the resort and its service areas grew. Most people living here are from mainland Mexico and a growing number are from the rest of America and Europe.

In Cancún there are about 140 hotels with 24,000 rooms and 380 restaurants. Four million visitors arrive each year in an average of 190 flights daily. The hotel zone is one of the most exclusive internationally, with upmarket restaurants, bars, and the like which have catered for quite a number of the rich and famous. The hotel zone tends to be rather expensive as it is aimed at visitors and relies on the all inclusive hotels to keep them all in this area allowing prices to soar. Downtown is home to less expensive places to shop like Walmart, Comercial Mexicana and Soriana, not to mention several flea markets like the one in the hotel zone.

Around March and April, Cancún experiences a flood of college students (usually from the United States) who travel to Cancún to party. For just about all of these students, drinking alcohol is usually the reason why they come to Cancún. The drinking age in Mexico is 18; while in the United States, it is 21.

Downtown Cancún gives us a different aspect. There are also many clubs for all types of people, including gay clubs like Karamba or Glow, but the hotels are more accessible to all types of travelers, including some with lower rates. International brands in Downtown area are Radisson Hacienda Cancún, Best Western Plaza Caribe, Oasis America.

Cancún's hotel zone also has an interactive aquarium where visitors can see the marine diversity of the area, swim with dolphins and feed sharks. Here and there in the hotel zone are some ancient ruins.

The main language in Cancún is Spanish, although English is widely spoken throughout the tourist areas. Mayan dialects are also spoken between some workers and people born in the Yucatán peninsula.