Guatemala is called The Country of Eternal Spring, and this has good reasons. Weather in Guatemala is good almost all the time, sure global warming has taken its toll here also, and now it is hotter than it used to be, but all around the year we have moderate weather, when it rains a lot it is usually not for long, there is no snow (except for very extreme occasional occasions, once in a decade in very high places).
The season in Guatemala are very peculiar, and not what you may expect. There are two identified seasons Summer and Winter, Verano e Invierno. Summer is called to the dry season, from November through May or June. Of course is not that simple either, as Verano is also called to the days around Holy Week or Semana Santa (March and April), which are usually the hottest days of the year. So how do you differentiate the long summer from to the summer in Semana Santa, I don’t know; the coldest days of the year, are also part of the summer, December, January and February. Winter is called to the rainy season, From May/June through November, it starts and ends with the rain.
Temperature here is measured in Celsius Degrees or Centigrade. To convent from Celsius to Fahrenheit you multiply by 9, then divide into 5, and then add 32:
°C x 9/5 + 32 = °F
To convert from Fahrenheit to Celsius you first subtract 32, multiply this number by 5, and divide into 5.
(°F – 32) x 5/9 = °C
You can find more weather information (in Spanish) at Insivumeh. The following map is running at that site, and linked here. Place the mouse over the icons to see more data.