It's hard to dress for the weather lately because the temperature changes a lot from the daytime to the evening.
It's hard to know what to wear these days because the temperature goes down a lot at night.
ーIt's hard to dress for the weather lately because the temperature changes a lot from the daytime to the evening.
「昼と夜の気温がかなり変わるので、最近天気に合わせて身支度するのが難しい」
to dress for the weather で「天気に合わせて身支度する」
temperature で「気温」
ーIt's hard to know what to wear these days because the temperature goes down a lot at night.
「夜、気温がかなり下がるので、最近何を着て良いかわからない」
it's hard to know what to wear で「何を着て良いかわからない」
to go down で「下がる」
ご参考まで！
カナダ 
