The 7% difference in insolation between perihelion and ahelion (a figure I've seen mentioned in multiple places) seems like it would be significant for sunburn and skin cancer, at least at the population level.

I found an ABC article that doesn't specifically say the 7% figure, but mentions perihelion as a factor in 10% higher UV in Australia. It downplays the role that extra 10% plays in our melanoma rates, though, and I suppose that's fair, I don't think anyone's getting caught out by burning 10% faster, because they would have gone inside 10% sooner if they had known, haha

Together, Professor Whiteman says, these factors mean Australia's UV is "probably about 10 per cent higher on average" than the equivalent latitude in the Northern Hemisphere.

"That would mean for people living in Brisbane it is higher than for people living in Miami in the US, and for people in Melbourne, it's higher than for people living in Athens, Greece."

While a 10 per cent increase in UV is significant, and might account for that sting in our summer sun, reasons for Australia's high melanoma rates are more lifestyle-related, he says.

source: https://www.abc.net.au/news/science/2025-02-04/sun-summer-uv-sunburn-skin-cancer-australia-ozone-layer/104870806