在中國(guó)農(nóng)歷中，立秋意味著夏天的結(jié)束和秋天的開始。

In Chinese lunar (月亮的)calendar (日歷),the Start of Autumn means the end of summer/fall and the beginning of autumn.

立秋帶來的首先是天氣變化，氣溫逐漸下降。

First thing,which is brought by the Start of Autumn is the change of weather.

The temperature drops gradually.

人們看到樹葉開始變黃飄落時(shí)，知道秋天已經(jīng)來臨，這就是所謂的“一葉知秋”。

When people see(that) leaves turn yellow and start to fall,they know that the autumn has arrived. This is called“one fallen leaf indicates/show the autumn”.

但此時(shí)酷熱的天氣并未完全結(jié)束，高溫通常還會(huì)持續(xù)一段時(shí)間，被稱為“秋老虎”。

However ,in this time ,the hot weather isn't completely over.The heat usually lasts for a while ,know as “Tiger of the autumn”.

in summer

at ＋具體時(shí)間

on 在某一天 on your birthday

立秋對(duì)農(nóng)民意義重大，這是各種秋季作物迅速生長(zhǎng)、開始成熟，收獲的季節(jié)即將到來。

The Start of Autumn is significant for farmers.In this time ,all kinds of crops/plants/things of autumn grow quickly and start to mature(成熟v/adj). The season of harvest(收獲，收割) is about to come.