Usually, August 1st is the beginning of the end for noctilucent clouds in the northern hemisphere. Weather conditions at the top of Earth's atmosphere shift in August, making it more difficult for summertime wisps of water vapor to crystallize around specks of meteor smoke.
As August begins in 2018, however, noctilucent clouds are still going strong. Just this morning, Vesa Vauhkonen photographed a bright display over Rautalampi, Finland:

© Vesa VauhkonenNLCs over Rautalampi, Finland
"Night-shining clouds over the lake of Konnevesi were very beautiful--the best ones I've seen in many years," says Vauhkonen.
A similar display appeared over the Talkeetna Mountains of Alaska. "They were the best noctilucent clouds I've ever seen,
extremely bright," says eyewitness Tempy Larew.
Comment: Late-season surge in Noctilucent Clouds produces stunning displays Last month an English astronomer reported photographing more noctilucent clouds in six weeks than in the last three years. See also: Are noctilucent clouds increasing because of the cooling climate, and the rise of fireball and volcanic activity?