Green speed is set by tier (e.g. free weeklies) or for all participants (e.g. CC tourneys).
The only varying condition is wind AFAIK.
We don't get the same wind on ever hole for every player, not even when playing multiple times, but you get a class of winds, like moderate or heavy. The translation to wind speeds differs from course to course, like STA will have stronger winds then MER for example.