This is the 30th most frequent Korean word.
이런
"이런" means "this kind of" or "like this."
In this sentence, "이런" modifies the noun "날씨" (weather) to indicate a specific type or characteristic of weather being referred to as "this kind of."
이런 날씨는 정말 드물어요.
Such weather is truly rare.
"이런" in this case specifies the type of "상황" (situation), signaling a scenario under discussion or assumed to be understood by the listener.
이런 상황에서는 조심해야 해요.
In situations like this, you should be careful.
Here, "이런" is describing "문제" (problem) and emphasizes a repeated or familiar type of problem, giving a sense of frustration or curiosity.