秋高气爽 qiūgāo-qìshuǎng

[balmy autumn day;fine autumn weather;sky in autamn is high and atmosphere pleasant;the clear and crisp autumn climate] 形容秋天气候清明爽朗

方拟秋高气爽,遣将西征,…——清· 梁绍壬《史阁部书》