How soon does skin cancer appear after being exposed to uv rays?

No time frame: We are all exposed to uv rays daily. It can take years to manifest a malignancy as a result of uv exposure.

Variable: In certain inherited forms of skin diseases, uv exposure can result in cancers in a very short time. However, in general, years of sun exposure (uva/uvb) are required before skin malignancies develop. Squamous cell carcinoma, basal cell carcinoma and melanoma all have uv exposure risk relationships.

Variable...long time: It depends a lot, but usually skin cancers occur months, but usually more like years after exposure. Risk of skin cancer is due to cumulative exposure to sun.