To hear sirens in your dream, stands as a mark for stressful situation or hidden problem. Any of these conditions is giving you much stress. The sirens in a dream may alert you to get attention in order to find a solution for problem at hand.
Dream dictionary: Sirens dream meanings
The dream of hearing sirens in a dream, denotes to things you are afraid of something that gives you lots of tension. The dream could also be a warning for a dreamer to focus on some very serious matter.