Here I was thinking it was an awfully cold office temperature.

18 F is -8°C

why the down vote for use of humor?

I didn't downvote you, but probably because it didn't contribute anything to the discussion.

These days, the only jokes that I've noticed not being downvoted are those that are a certain brand of witty and intellectual. Or they at least give the appearance of contributing to the discussion, even it doesn't survive detailed scrutiny.

This cultural dynamic seems to work out alright, given the other characteristics of HN. It would be hard to do better I think. Overall, I'm personally pretty happy with the level of discourse on HN.

I'm surprised that you are surprised, being a member for 6+ years. Was it different before?

This isn't Reddit or Slashdot, it's not enough to cause a mild chuckle. Also your humor isn't very funny.