I live in Palm Desert, our temps are about 5-10 degrees warmer than LV, but I go out there every few weeks for work. I always plan to bring my bike but it seems like the local clubs go out later than I would like, probably different in the summer.
We're forecasted for 122 here today. We ride at 6am, this morning it was 87 when I went out but similar to LV it's pretty dry. I'm not a fan of riding in the dark but 5:30 am would be beautiful in Vegas I would think!