"July, August, September"

Translation: Lipiec, sierpień, wrzesień

[YariMsika]

Wrzesień is really hard to pronounce :)

[frandogk3]

Does anyone have any word origins on these, and the other months, to make them easier to remember?

[Jellei]

Well, the names are so old that for half of them the word origins don't mean anything anymore for contemporary Poles ;) The ones that are clearer: kwiecień is from kwiat (flower), lipiec is from lipa (the tree linden), sierpień from sierp (a sickle, like in the USSR flag), listopad is a month when leaves (liście) fall (spadają, opadają).

[frandogk3]

That's awesome! Exactly what I needed. Very helpful, thanks.

[immery]

also

czerwiec if for some insects/maggots but is related to czerwony=red. https://en.wikipedia.org/wiki/Polish_cochineal

wrzesień is when heather = wrzos blooms

październik is from paździerz= which is the waste from flax

grudzien is probably from gruda= clod, hardpan

[frandogk3]

Wonderful! That is great stuff. I love the connections to the natural world. Thanks!

[KirillKozlovsky]

Also, "luty" means "severe" or "harsh", especially when referring to cold (at least it does so in my native Russian), and indeed, the weather in February is quite harsh and cold in Eastern Europe.

[margotgm]

i really do not understand why the names of months change when they are not in a sentence indicating objective or genetive

[immery]

they change like all nouns change in Polish.

Here you have nominative.

declension table of lipiec
declension table of sierpień
declension table of wrzesień