We decided to study the problem in detail and analysed the months that involve transitions between two successive seasons: February-March, May-June, August-September, November-December.
For instance, for the Summer-Autumn transition, we compared the average temperature of the second half of August of the period 1961-1990 with the average temperature of the first half of September in every year between 2001 and 2019.
After studying all these transitions, we came to the conclusion that, in the last few years, the average of the first half of September exceeds the average of the second half of August from the reference period. Therefore, we could be witnessing an extension of Summer with 15 days, the seasons no longer being the classical ones.
In the preliminary phase of the project we studied all the transition periods between seasons (Winter-Spring, Spring-Summer, Summer-Autumn, Autumn-Winter), each detective studying the transitions in 3 years.
We found interesting changes on the Summer-Autumn transition. To study the problem in detail, we extended the analysed period (1961-2019), our attention being focused on the second half of August and the first half of September, and the results can be seen above.