Here in the north we do see differences in patterns. Some will show more pattern with warmer temps, others with cooler and some are consistantly patterned regardless of temp. The change in temperture and how it relates to the pattern can be different for each cv or seedling. Some may change at 65 while others 55, the question adding to this is when does this temperature change need to occur to change the pattern, the day before a bud opens, 2 days...does the heat/cold on the day it opens change the pattern? Jerry Hyatt is one that shows a heavy silver overlay with cooler nighttime temps. When it gets warmer the silver breaks and shows the leopard or cheetah spotting pattern. I haven't recorded the timing or temps for changes, just simple observation.
This older sdlg below only showed the arrows when the temps were below 55 for at least 2 nights.While interesting, the 55 temperature for pattern was not a trait I wanted so it was composted several years ago.
And this seedling has been consistantly the same from it's maiden bloom in '07 first image to the image from last year regardless of temp. Every bloom is the same. This is one I have been working with.