Which of the following is typical of the lower HF frequencies during the summer?

During the summer months, thunderstorms are much more frequent and widespread. Lightning strikes generate broad-spectrum radio frequency energy, which is heard as "static" or atmospheric noise (QRN) on radio receivers. Lower HF frequencies (like 160m, 80m, and 40m) propagate this noise very effectively because these longer wavelengths easily travel great distances along the Earth and via the ionosphere. As a result, the lower summer bands are often incredibly noisy compared to the winter months. Distractors suggesting poor propagation at *any* time of day are incorrect, as nighttime propagation still happens but is just masked by this high static level.