As for the sunrise, the sunsets are also spectacular in El Chalten.
Mainly at the mountain peaks such as Fitz Roy and Cerro Torre, as they permanently are "decorated" with the clouds at their peaks.
Dress Code: Nothing in specific, warm clothes, as it can get cold in the night.
A good cup of hot tea can help staying awake the whole night and watch the million star sky :-)
Due to the fact that there is nothing but wilderness and nature along 200 km and more around of El Chalten, sunrises and sunsets are spectacular !!
Plus the light has a different "view", due to the clarity of the air.
This sunrise we had often there, just as the european "Alpengluehen".
Dress Code: Something warm to wear, as these sunrises are mainly when the night was cold :-)
And look, how smooth the lake surface had been :-)