May but May not

I noted in passing not quite a year ago, on May Day 2007, that the following trees and shrubs were all in full bloom in my yard:

• Bradford pear
• Magnolia
• Weeping cherry
• Forsythia
• Azalea
• Quince
• Andromeda
  

Today is April 23, and all of the same plants are again in full bloom, with the wisteria again hot on their heels. I would not suggest that spring has advanced eight days in the course of a single year: obviously, there is normal variation in weather from year to year that does not measure an equivalent change in climate. Nonetheless, this year it is March showers that have brought forth April flowers.