EDIT:
Apparently it's never directly-referenced that there is ice at the poles, but post-canon sources suggest there might be very limited collections of frozen water there.
Probably still not snow - but I could entirely be wrong.
We can all moderate our expectations to whatever extent feels right. :D
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Hi hi friends -
I wanted to drop this here, just so folks can be excited without unfairly getting their hopes up:
On Arrakis, Polar Caps != Snow
"Polar caps" refers to the "top and bottom" of a planet: it's the center point on which the planet is rotating.
On Earth, the North Pole and the South Pole mean "snow", because our planet is full of water and our poles are super cold, but there is not enough water on Arrakis to have snow (and it's not clear if Arrakis poles are cold).
(And if they had snow on Arrakis, everyone would live there, to be nearer to the water)
(Also: if Funcom announced snowball fights on Dune, lemme know I'm off base. But they've been pretty good about sticking to the overall canon, so I suspect we're not going to get a "snow" dlc)