Okay, I think I've finally nailed down my algorithm for determining if it's warm enough to eat lunch outside:
1. Can liquid water exist?
2. What about in direct sunlight?
3. What if it's like, in a black bowl, in direct sunlight?
if any of the answers are yes-like, I'll eat outside. If they're all no I'll think about eating in the breakroom, then go eat somewhere else instead.