Passport valid for at least 1 year after date of entry is required by all except the following: (a) 1. nationals of the USA holding a certified copy of a birth certificate and photo identification

The Mexico unit of currency is the peso. but you'll need some usdollars in ash or or travelers cheques. Most of international Credit cards ( Visa, Master Card, American Express ) are accepted everywhere.

In the south of peninsula, tropical weather.
In the north, dry weather with official raining season from june to october.
>>>> Weather

No vaccine required.

It is used to leave 15% tips in restaurants.
For taxis, most of the time, there is a fixed prices system,
posted in all the taxi ranks and the hotels, restaurants and other touristic places .