I am looking at a history of daily min/max temperatures for the past ~40 years of a specific city (the variable precipitation isn't needed). I imported the CSV file with the aim to calculate an average for the low and high temperature for each winter (I consider the range November-March as winter). So I suppose a solution could be to loop over the years and maybe create a column which consists of "Winter&year" (for instance the first of december 2018 fell in winter 2018 and the 23rd of February 2019 fell in winter 2018 too). I found plenty of examples to aggregate days/months into seasons but nothing where the year changes and I actually struggle with that bit.
The structure of the data is the following:
Could anyone point me to the right direction?
Many thanks