County Level UV Exposure Data for the Continental United States

Graphic illustrating the average global solar radiation levels in the United States.

Exposure to ultraviolet radiation has long been recognized as the most important environmental risk factor for melanoma [1-2]. Exposures in early childhood may be most important [3] and there is evidence that cumulative UV exposure and the time spent outdoors may increase melanoma risk [4]. The following dataset has been developed in response to a need for an objective metric of individual UV exposure for which the accuracy of exposure estimates is known. Additionally, these data can be mapped using the online NCI Cancer Atlas tool (select Data Category: Screening and Risk Factor – US County Data).

UV Data - Counties (XLSX - 143 KB)

Peer Reviewed Publication Describing the Methodology behind the UV Exposure Dataset


  1. Etiology, epidemiology, risk factors, and public health issues of melanoma. Elwood J.M., Koh H.K. Curr Opin Oncol. 1994, 6: 179–187.
  2. Melanoma etiology: where are we? Tucker, M.A., Goldstein, A.M. Oncogene. 2003, 22: 3042–3052.
  3. Cutaneous malignant melanoma and indicators of total accumulated exposure to the sun: an analysis separating histogenetic types. C.D. Holman, B.K. Armstrong. J Natl Cancer Inst. 1984, 73: 75–82.
  4. Influence of sun exposure during childhood and during adulthood on melanoma risk. Autier, P. Dore, J.F. Int J Cancer. 77 (1998) 533–537