sulfurous

"an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "caustic jokes about political assassination, talk-show hosts and medical ethics"; "a sulfurous denunciation"; "a vitriolic critique";

"the summer was sultry and oppressive"; "the stifling atmosphere"; "the sulfurous atmosphere preceding a thunderstorm";