Are they designed for cold and warm weather...
Are they designed for cold and warm weather riding?
Depends how cold you're talking. Generally speaking these are best for warm weather.
Yes, all knickers are basically meant for Spring/Fall riding, at least in the North, as part of your legs are exposed; and so the material used is of light to medium weight and tech.
If it's particularly nasty or wet out, you can wear Gore's ALP-X 2.0 GT pants OVER your tights, knickers, or shorts (they do offer a 'short' version of these) for added rain/wind protection (size-up so they can fit over top easily). Also, if you get these, get a pants leg strap to keep your right pants leg out of the chain!
For winter, look for something that is windproof (such as Gore's *Windstopper products), and listed as being "thermal".
Hope this still helps.