Now is the ideal time to view Noctilucent clouds. These very high, and rather mysterious, clouds are at their best between June and August in the Northern Hemisphere. They are lit by sunlight in the middle of the night and tend to be a milky-blue and very thin so are only noticeable against the dark night sky. If you see them, you should report your observations Noctilucent Clouds Observer’s Group

You can see more of these clouds on the gallery page. And read more about them here