that temperature

There is a certain temperature at which the little yellow flowers (weeds) along the side of the roads in Berkeley just start to open up to the sunshine, while others stay closed, raised in anticipation. And that temperature must be within a degree or two of the temperature at which students decide that it's too cold to sit outside at Strada, even when white petals are falling from branches that bear new green leaves. Too warm to stay home, too cool for a t-shirt. The perfect temperature?