Background: Overexposure to ultraviolet (UV) radiation has increased skin cancer incidence and the risk of sunburns, especially during the summer months. Objective: Identify the frequency and factors associated with sunburns in a sample of beachgoers in the northern coast of Peru. Methods: We conducted a secondary data analysis of a previous study that assessed the awareness, behavior and attitudes concerning sun exposure among beachgoers. We included adults between 18 and 59 years who went to a beach in northern Peru during summer (March 2018). Three generalized linear models of the Poisson family were constructed to evaluate the factors associated with having had at least one sunburn last summer. All regression models reported the adjusted prevalence ratio (aPR) with their respective 95% confidence interval (95% CI). Results: Of a total of 402 participants, 225 (56.0%) had one to five sunburns and 25 (6.2%) had six or more. Beachgoers who were 1-15 days (aPR: 1.16, 95% CI [1.05-1.27]) or more than 15 days (aPR: 1.22, 95% CI [1.09-1.36]) exposed to the sun on the beach had a higher frequency of at least one sunburn. The non-regular wearing of a hat or cap also increased the frequency of sunburns (aPR: 1.06, 95% CI [1.01-1.12]). In contrast, those who had Skin Phototype III (aPR: 0.94, 95% CI [0.88-0.99]) or IV (aPR: 0.69, 95% CI [0.63-0.75]) had a lower frequency of sunburns. Conclusion: Three out of five beachgoers had one or more sunburns in the last summer. The factors associated with a higher frequency were the time of sun exposure at the beach and the non-regular use of a hat or cap. Type III-IV skin phototypes were associated with a lower sunburn frequency.