When to Go
Many countries make the claim, but in Guatemala it truly applies: You'll find no bad time to visit, although some seasons are more ideal than others. For near-perfect weather in the much-visited central part of the country (Guatemala City, Antigua, and the highlands), consider a trip during the November–April dry season. These are also the months when Guatemala's most famous religious festivals (the Day of the Dead, the Burning of the Devil, the Santo Tomás celebrations in Chichicastenango, Christmas, and Lent and Holy Week in Antigua) take place. However, don't feel the need to avoid the rainy season; rains rarely impede travel here, and will likely not interfere with your trip. Also, don't forget that the rest of the country (Las Verapaces, El Petén, and the Atlantic and Pacific lowlands) has a less distinct division between rainy and dry seasons.
Guatemala isn't a "fun in the sun" kind of destination, and there's little distinction between weather-based high and low seasons. Lodging and tour rates remain fairly constant year-round. (Some hotels at popular destinations such as Antigua and Lake Atitlán raise rates on weekends.) Two big exceptions to this rule are Christmas and Holy Week. Make reservations weeks or months in advance if you plan to travel during these times, and be willing, even then, to settle for alternate choices.