I'm not sure about daphnes, but I suspect that they bloom based on the time of the year, not on the temperature. And you're right: when flowers bloom that way, it's to prevent their blooms from being damaged by a last-minute snowfall. I've spent the last month terrified of one last big freeze down here, because so many of our most beautiful trees were already starting to bloom in the middle of February. This isn't to say that we couldn't get one last blue norther that freezes everything (we've had it before, all the way to the beginning of April back in 1997), but if we haven't had that last freeze by St. Patrick's Day, we probably won't have one until next December.

By the way, I'm jealous of the plum blooms. We don't have a huge number of plums in the vicinity (lots of pears, peaches, and mulberries, but strangely no plums), and I remember as a kid how sweetly they smelled.

Lucky you Jack. My daphne is just about done blooming, and along with the flowers will go the wonderful scent. Enjoy it as long as you can.