but no way at sea level.

Today in Santiago is hot and sweltering. I don't know the exact figures, but I would guess 85 square (85 Fahrenheit and 85 % humidity). This is the coolest time of year here, although admittedly this is a little warmer than normal.

Of course the "felt" temperature at the beach is better if there is a sea breeze, but I doubt that it dips to 70 F. there, even at night.

I think that the coolest I have seen was 55 F. at night - in the mountains.

You definitely won't need your fur parka here. The only jacket I ever bring is a very thin, but waterproof one. It stops both the wind and rain, which is all you need.