Due to the country’s proximity to the equator, temperatures in Colombia are quite stable all-year-round and vary per altitude rather than season.
Being close to the equator means tropical and hot weather.
Days are cool and nights can be freezing when in high altitudes (7 to 17ºC) however in low-lying areas temperatures are mild and warm (24-28ºC).
Weather in Colombia is also marked by the rainy season which runs March through June and then again between September and November.
The Amazon is generally wet the entire year.
In a nutshell, Bogotá due to its high altitude will get cool temperatures, Medellín mild climate and Cartagena, on the coast, will have a tropical climate.