Parent is referring to snow in the environment, not on the lidar itself.

When snowing in Toronto you usually cannot see the painted lines on the road, there's just the lines from cars driving through the snow that you follow. Sometimes two lane roads become an unofficial one lane road depending on what feels safe.

The falling snow also bounces the laser pulses(?) back at the lidar. Snow fall can be pretty heavy and make it difficult to see objects far ahead. Not sure how well their handling of rain ports over to snow, but it will be interesting to see!

Afaik the already do this. But another problem is that falling snowflakes reflect lidar pulses and heating doesn't help in that case