Normally in August, summertime noctilucent clouds (NLCs) begin to fade as weather conditions become adverse in the mesosphere. This year, however, the northern hemisphere 2018 NLC season is still going strong, with four times more NLC reports than in the same period in 2017.
The first known observation of noctilucent clouds dates back to 1885, two years after the 1883 eruption of Krakatoa. At first, they were only seen at high latitudes, but have recently started appearing ever lower in latitudes. While science still doesn't provide a definite answer to why this is happening, previous studies have shown that NLCs can intensify during solar minimum.
During solar minimum, the Sun's extreme UV output decreases. This has two effects: (1) the upper atmosphere cools and (2) the upper atmosphere keeps more of its water molecules, which are normally split apart by UV rays. More water + less warmth = more icy noctilucent clouds.
If this is what's happening, then more NLCs may be in the offing as solar minimum continues to deepen in August 2018.
Credit for Images at Top of Page: Adrien Mauduit, Courtesy of The Watchers