Here in OH, you can tell when spring is here once you hear the birds singing early in the morning, and you see all the flowering trees are in bloom. And the change is usually very abrubt. Last week, I was scrapping ice off my car in the morning. This week, its in the upper 70s everyday, and its warm enough to leave the back door open all night (my dogs love this time of the year for this reason). I can also tell that it is spring because the traffic gets heavier - I'm not entirely sure why that is though.

__________________
Tiger got to hunt, Bird got to fly, Man got to sit and wonder 'Why, why, why?'
Tiger got to sleep, Bird got to land, Man got to tell himself he understand.
~Bokonon