Why Does Skin Pigmentation Increase In Summer? During summer, many individuals experience tanning, dark spots, uneven complexion, and skin dullness. If you want to know why pigmentation increases in summer, the biggest reason is strong ultraviolet rays from sunlight. The skin increases melanin production in summer as a protective response, https://sites.google.com/view/drnikita-patel/blog/why-does-skin-pigmentation-increase-in-summer