More precisely in Almagro, as I can only speak about the view from my Windows... :)
How rare is this...? VERY rare. It "never snows" in Buenos Aires. According to what I found in the Net, the last recorded snow was June 22, 1918!!
The day started chilling cold, and it was only a handful of foreign tourists and myself at the Plaza de Mayo and surrounding areas...
And by later aftenoon, first a timid then full snowfall decorated the tops of the highest buildings
By night, even the international media started paying waking up to the newsworthyness of this ocurrence: