Am I the only one who always gets those two confused? (Also in German: Länge und Breite. I can never remember off the top of my head which is which.)
My workaround is this: there's a set phrase "in these latitudes" / "in diesen Breiten" which refers e.g. to where certain plants grow or animals live, so I know that latitude/Breite has to refer to how far north or south of the equator you are (since that influences temperature and climate), and so longitude/Länge has to be how far east or west of the Prime Meridian you are.
So my latitude is about 53° N and my longitude about 10° E.
How do you guys remember the difference?