The correct answer when translating from Masika to English was season of heavy rain. But when I translated season of heavy rain in English to masika, it won't accept it, insisting on msimu wa masika.
Right, Duolingo is pretty inconsistent with this sort of thing. Particularly in this lesson. There is a similar translation in this skill, that will grade wrong for including "msimu wa."
msimu wa masika = spring season
I agree with the comments below. There is real inconsistency in this weather lesson.