Answer:
It is a freckle.
Ephelis definition:
Freckle Dermatology The most common pigmented lesion of young light-skinned Caucasians, often of Celtic stock, consisting in light brown 1-10 mm macules which fade in winter, and are accentuated in summer
Freckle definition:
Yellowish or brownish macules developing on the exposed parts of the skin, especially in people with light complexions; the lesions increase in number on exposure to the sun; the epidermis is microscopically normal except for increased melanin.