The neat thing about being at the equator is that temperature is more to do with your altitude than any other factor. If you want to be hotter in Colombia you just go downhill. Higher up if you want to get colder. Bogota is closer to 15° all year since it's a few hundred meters higher up in the mountains than Medellin. Cartagena is closer to 29° since it's right on the coast at sea level.