Why Does Skin Pigmentation Increase In Summer? Hot weather often causes pigmentation, tanning, and patchy skin tone in many people. If you want to know why pigmentation increases in summer, the biggest reason is strong ultraviolet rays from sunlight. During summer, the skin produces more melanin to protect itself from https://medium.com/@rameshjain5454/why-does-skin-pigmentation-increase-in-summer-599cc6b6d7c5