lonely planet shows a picture that electrical outlets are the same as in the usa and that it is the same voltage. After there places where it might be 220 and need a plug adapter?
Answer: The outlets run on a standard 120v/60 hz current, so an adapter is not needed. However, the majority of outlets in Guatemala are only 2 pronged, so if your device has a third grounder prong, you may need an adapter. Here is more information: