It was late August and the harvest had been safely gathered in.

已是八月下旬，庄稼都妥善收割完毕。

《牛津词典》

Dry August and warm doth harvest no harm.

八月干热却利于收获。

youdao

He won't harvest the biggest ones until later in August and September.

直到八月下旬或是九月他才会采摘这些个儿大的西瓜。

youdao

At Le Domaine de Manon, outside of the Grasse city limits, tours of flower fields are given during the harvest, which is generally May for roses and August through mid-October for jasmine.

BBC: Perfume in Provence: Visit, smell, create