return of the rainy season; rainy season returning after a clear spell
Refers to the rainy period that sometimes occurs after the end of the main 梅雨 (tsuyu) season, typically in July. Synonymous with 戻り梅雨 (もどりづゆ).
See also: 戻り梅雨
This year the return of the rainy season is long, and the laundry won't dry.
Even though the rainy season ended, the return of the rainy season has brought more rain.
The main rainy season (June–July). 返り梅雨 is a secondary rainy period after the main season ends.
Compound of 返り (kaeri, 'returning') + 梅雨 (tsuyu, 'rainy season'), literally 'returning rainy season'.