@tjukanov Love the challenge! I've looked for the shape of your data on a number of maps but can't find anything that fits. South Korea is close.
How about a small hint? Why are there virtually no points in the vertical middle space of the data?
@FranLoew @ma_salmon You compared two single years here. I adjusted your code to get the median temperature over a course of 10 years. The differences, while still present, are not as large anymore
@FranLoew @ma_salmon some of the warmest cities (Freiburg, Heidelberg,...) are in Baden-Württemberg but that state has large mountain ranges. Would be interesting to find how they calculated the averages