noun which may take the genitive case particle 'no', na-adjective, noun
rainy; prone to rain
Describes weather or a period that tends to be rainy, often with a nuance of 'more than usual' or 'unfortunately rainy'. Used attributively with の or as a na-adjective.
今年の梅雨は雨がちの日が続いている。
This year's rainy season has been continuing with many rainy days.
明日も雨がちな天気でしょう。
Tomorrow's weather will likely be rainy as well.
雨模様 also means 'looks like rain' or 'rainy weather', but focuses on the appearance or likelihood of rain, while 雨がち emphasizes a tendency or frequency of rainy days.
A more straightforward phrase meaning 'rain is frequent'; 雨がち carries a slightly more subjective or evaluative tone.
Compound of 雨 (rain) and the suffix がち (tending to, prone to), which derives from the verb 勝つ (to win, to be predominant).