The notes are wrong, aren't they? It says "haru natsu fuyu biyori" but then goes on to say that it would be "spring, summer, autumn weather". The issue is that "fuyu(冬)" means "winter". Autumn/fall is "aki(秋)", so it should be "haru natsu aki biyori", which is further strengthened by how the irregular reading mentioned is "akinai biyori", right? At the very least, fuyu shouldn't be there as it breaks the flow, after all, natsu isn't followed by fuyu.
Just bothered me, not a big deal at all though.
The awkard thing is that I can never be completely sure because while I'm learning japanese and I've become able to read fairly well, I'm still a long way away from proper mastery and real fluency. Therefore I can never be sure if it's some weird thing I haven't heard of yet, but I highly doubt that in this situation since they even wrote out what it was supposed to mean in english.