The best period to go to South Korea is from September to November. It's at this time of year that the weather is the most pleasant and the natural colours are the most beautiful. It's also possible to go to South Korea in winter to see it covered in snow. Though spring can be pleasant too, the hotels and tourist sites are often crammed: it's during this period that Japanese tourists choose to visit. Summer is the most touristy period, but it's sometimes stiflingly hot and it can rain heavily in July: best to avoid it.