I worked on a project related to modelling UV and skin cancer rates. And what I learnt there is that that big thing that causes skin cancer isn't so much total

I worked on a project related to modelling UV and skin cancer rates. And what I learnt there is that that big thing that causes skin cancer isn't so much total UV exposure over a year, but a sudden switch for long periods of no sun to a period of intense sun. You see this especially in the Nordic countries where it isn't uncommon to go from 4 month of getting essentially no sun to 10 days of spending 10 hours a day in a bathing suit on a beach in Thailand or Bali.