Back home in PA I often considered the arrival of the robins and the sprouting of tulips as the first clear signs of Spring.  Where I currently live in Japan I use to the blossoming of the ume trees to signal that Spring is here.

The ume trees have many small white or pinkish, fragrant, sweet smelling flowers a few weeks before the sakura (cherry blossom) trees explode to life and take center stage.  I really like cycling down the street and catching their sweet scent in the air.