When I should winterize our TT?

bobndot wrote:
You need to watch your night time temps. When you expect those temps to drop below freezing , its time to winterize.
Unless you are not planning to use your rig, then do it now and you won't have to worry about anything.

Good advice here.
I have been RVing for 25+ years and I still have the same question...
"When should I winterize?"
All I am sure about is that I don't need to winterize June-Aug. and that only is true for where I live. The rest of the year...????