The best time to visit these islands is during the summer months, which will have a considerably warmer temperature. However, if you are looking to get into the extreme cold and wander around outside in the chill, then you can visit these islands during the winter months. The best time to visit would be during the summer months or during spring so that you do not encounter any sort of problems while travelling back and forth to these islands. As far as possible you should research as much as you can as to what you need to know before you leave for these islands, including the requirement of whether you would need to acquire a visa or other documents besides your passport.