秋高气爽

qiū gāo qì shuǎng

clear, crisp autumn weather

Character by character

秋qiū
autumn

高gāo
high

气qì
air

爽shuǎng
crisp

十月秋高气爽，正是爬山的好时候。

October is crisp and clear, the perfect time for hiking.

Tone: positive (praise).

High sky, fresh air: classic National Day holiday weather in the north.

Learn it in context

This idiom and thousands more are in Learn Chinese with Bao, with audio, pinyin and drills that make them stick.