Lukewarm or tepid; mildly warm in an unpleasant or unsatisfying way (e.g., air, bath).
梅雨の時期は生暖かい風が続くことが多い。
During the rainy season it's common to have persistently warm, muggy winds.
生温かいお湯に入ると、かえって気分が悪くなることがある。
Getting into lukewarm water can sometimes make you feel worse.
彼の生暖かい反応に、もう少しはっきりした答えが欲しかった。
I wanted a clearer answer — his lukewarm response was unsatisfying.
窓を開けると生暖かい夜気が入ってきた。
When I opened the window, warm, muggy night air came in.