In early summer the weather is quite warm but there may be some rainy days and in August it can get quite cool in the evening. Throughout late June and July, the temperature increases, so you will need to bring a sun hat and sun protection if you need it. Most people find the climate very agreeable.
In winter, even if the temperature is as low as minus 30 degrees Celsius, it is not a problem if you prepare carefully and bring the appropriate clothes. The atmosphere is not damp so it is certainly more agreeable than spending a cold, damp winter in the UK. The winter camp facility is very warm.