我在海边的一个小镇上长大，那里夏天炎热而阳光明媚(高达30-35°C)，我记得我自己和我的朋友和亲戚每天在户外度过12个小时。我们从不需要防晒霜，也从不使用它。人们认为，皮肤在晒日光浴的第一天会被晒伤，因此采取了预防措施，即:“在阳光直射下晒三个小时后，穿上长袖衬衫”。我家乡的坐标是[46°45 ' 35″N 36°47 ' 04″E][1]。目前，我住在另一个小镇，非常靠近海岸，坐标[41°4 ' 9″N 73°51 ' 35″W][2]，我们有炎热和阳光明媚的夏天(高达30-35°C，有时稍微多一点)。我很惊讶这里的阳光有多么强烈。我们整个夏天都需要防晒霜，有一次我不得不在9月初在户外工作8个小时，我不知怎么地被晒伤了。鉴于我童年的经历，我不可能想象在夏天结束的时候我会被晒伤。我只是在夏天晒得很黑，然后我的皮肤就能抗晒伤了。 I wonder what is an explanation for this. One explanation could be that sun is more aggressive in my current town, than it was in my home town. But why? Another explanation, that there are some other factors involved, but I am not sure what these factors could be. If anyone knows what is an explanation for this phenomenon, I would be most grateful for your help. [1]: https://www.google.com.au/maps/place/46%C2%B045'35.0%22N+36%C2%B047'04.0%22E/@46.7597259,36.7822504,17z/data=!3m1!4b1!4m5!3m4!1s0x0:0x0!8m2!3d46.7597222!4d36.7844444 [2]: https://www.google.com.au/maps/place/41%C2%B004'09.0%22N+73%C2%B051'35.0%22W/@41.0691707,-73.8619162,17z/data=!3m1!4b1!4m5!3m4!1s0x0:0x0!8m2!3d41.0691667!4d-73.8597222