From what I've heard, we haven't had this many hot days in a row for several decades.
ーFrom what I've heard, we haven't had this many hot days in a row for several decades.
「聞いたところによると、こんなに暑さが続くのは数十年ぶりらしい」
from what I've heard, ... で「聞いたところによると…らしいよ」
we haven't had this many hot days in a row for several decades. で「こんなに暑い日が続くのは数十年ぶりだ」
ご参考まで!