Berlin(the biggest city) is miserable in this regard. My former tram line(M4) used to be 50:50 with old and new trams. In the last year before I moved, they had

Berlin(the biggest city) is miserable in this regard. My former tram line(M4) used to be 50:50 with old and new trams. In the last year before I moved, they had almost 100% old trams in there. Same goes for S-bahn, even new carriages are not equipped to deal with the weather. I dreaded using them in summer. The city has an excellent network in terms of coverage, but the trains are outdated.