Summer in the Colombian Andes can be a meteorological crapshoot.
Dry and clear periods, mixed with torrential rain, snow and high winds. Temps often hover around freezing during the day, but subsequently drop well below zero (celsius) at night.
Virtually all of the hiking during my recent trip was done at altitudes between 3,800 and 5,000 metres (12,467 and 16,404 ft) above sea level.
In hindsight, the one change I would make to my gear list would be to swap out the Merino 150 t-shirt I wore whilst hiking, for a long sleeve/zip-neck equivalent (i.e. extra warmth & more sun protection). Other than that, I was happy with all of my gear choices for the journey.