你必须在八月底前注册。

You need to enrol before the end of August.

《牛津词典》

我把他们寄给我的东西都填好，在八月底左右就回来了。

I filled in whatever they sent me, and I returned like at the end of August.

youdao

在充足的光线下，树林边缘的树木呈现出一种暗棕色的绿色——因为已经到八月底了。

The trees on the wood-edge were a darkish, brownish green in the full light—for it was the end of August.

youdao

and may come again like, towards like the end of August, it gets quite hot

可能热浪会再次来袭，一直到八月底，那会相当热，

关于伦敦的天气 - SpeakingMax英语口语达人

but it's not really, really hot. It might get hot like in end of August.

但是不会真的很热，可能会像八月底一样。

关于伦敦的天气 - SpeakingMax英语口语达人