Noctilucent clouds, also called polar mesospheric clouds or “night-shining” clouds, occur most often near the poles and occasionally at lower latitudes. The image above shows a satellite-based view of noctilucent clouds on June 16, 2021. According to Randall, data from NASA’s Microwave Limb Sounder indicates that conditions are favorable again this year for low-latitude viewing. High-altitude temperatures are lower than average and water vapor is higher than average, making it more likely that water vapor will condense into ice. The photo above shows noctilucent clouds as viewed from Bainbridge Island, Washington (47.7 degrees north latitude) on June 16, 2021.