For the past several years I've been watching the cold spells to see if they really do match up with redbud, dogwood, locust and blackberries blooming and amazingly enough they do. I think it was the week before last when there was frost on my windshield and the dogwoods were in full bloom.
It didn't warm up much, but this cold, rainy spell going on right now hit when the locust trees were blooming. If it keeps holding true there is only Blackberry winter left to go. Last year there was frost on my car just after the blackberries bloomed.
Amazingly enough I had 16 hits on my blog a couple days ago using the search term Locust Winter.