Part of planning your trip to Mexico will involve deciding what you need to pack and take with you. You want to be comfortable, look stylish and appropriate for the places you're visiting. A bit of thought beforehand about what clothing will be most appropriate for the destination, time of year, and activities you have planned will allow you to enjoy your trip without the discomfort of being inappropriately attired.
Mexicans may dress more formally, and in some cases, more modestly than people north of the border may be accustomed. Of course, you're free to dress as you wish, but if you choose to dress very differently from the majority of local people you may be singling yourself out as a tourist, and worse, you may be seen as being disrespectful to the host country.
Here are a few general guidelines about what to wear depending on your destination, the type of activities you plan to participate in, and the weather.
Depending on Your Destination
Inland, for example in Mexico City and in Mexico's colonial cities, people generally dress more modestly than they do along the coast and in beach destinations. Although it's changing a bit over time, women in Mexico's interior destinations seldom wear shorts, and men almost never do. Women who don't want to attract excessive attention from men would be well advised to avoid short skirts and shorts and revealing clothes in general, but especially when traveling alone. Lightweight pants and long skirts are good options, as are blouses and tops that cover your cleavage.
Sleeveless tops are acceptable, tank tops less so.
For coastal cities and towns, casual clothes and shorts and tank tops are generally acceptable on the street. If you're going to the beach or pool, take something to cover up on your way there and back—wearing swimsuits away from the beach or pool is generally considered inappropriate. A traditional shawl, called a rebozo, is a practical and stylish item of clothing that comes in handy in a variety of situations. If you don't have one to bring with you, it's something you can easily purchase in Mexico.
For restaurants or nightclubs, it is customary to dress a bit more formally. Some restaurants require men to wear long pants and closed shoes. The old adage "Men, wear pants. Women, look beautiful," still applies in some establishments. For men, guayaberas are generally a good option—you'll be cool and will be dressed appropriately even for formal occasions.
Depending on Your Activities
If you're visiting churches, short shorts, short skirts, and tank tops are frowned on, but longer, Bermuda type shorts and t-shirts are generally fine.
For visiting archaeological sites, comfort is key. Wear comfortable walking shoes. A closed toe is best for climbing pyramids and walking on sometimes treacherous surfaces. Although the weather may be hot, it's best to cover up to avoid excessive sun exposure and mosquito bites.
When it comes to adventure activities, of course it will depend on the type of adventure you have planned. For zip-lining, wear shoes that attach firmly to your feet so you don't risk losing them. Shorts that are long enough so that the harness does not chafe your skin is a good idea. If you have a white water rafting adventure planned, water shoes are the best, and quick drying clothes. You may want to wear a bathing suit under your clothes.
Check the Weather
A lot of people assume that the weather in Mexico is always hot, but that's not the case. Be sure to check the forecast for your destination before you leave so that you will be well prepared with a sweater or jacket and/or a raincoat if necessary. In southern Mexico, rainy season usually falls from spring through early fall. High altitude destinations such as Mexico City, Toluca and San Cristobal de las Casas in Chiapas can get quite cold, especially in the winter months, so be sure to pack extra layers.
In general you can't go wrong if you bring light layers in natural fabrics (cotton, silk or linen) that are comfortable, cover you appropriately and are breatheable in case it's hot or humid. These types of fabrics also wash and dry easily, so you don't have to bring too many pieces and can mix and match. If you need to buy some extra clothing, you can find department stores or other shopping opportunities in any larger town or city.