I've found that simple cold is not much of a big deal if you're dressed appropriately. Like down to the 30s maybe, here in the south. Warmups and standing and I'm cooking and would take off my outer jacket to do forms.
Wind, also, not a big deal. A little more feedback. If your root is so weak as to be toppled by normal winds at ANY point during your taijiquan form, please, come to florida so we can figure out what's broken and do a little hurricane work.
Cold wind is another matter, it rips through my clothes and just strips away the heat. If I don't have gloves then I just can't tolerate it.
The beach is always fun, you get wind AND shifting sands to stay steady on while stepping. Come train with me....
The cruise ship thing, also fun and challenging, haven't done that in years.
Too much sun and like any time you run the risk of burns, but a little bit of sun is nice.
I prefer a nice patch of smooth dirt ringed by grass under a nice tree with a little sun filtering through and a warm gentle breeze in the high 60s-low 70s