Is it possible that I’m seeing cherry trees flowering this early (mid-February)? Some have white flowers, and some are pink.
It is certainly true that things may be flowering early when we have a mild winter. In 2014, the famous cherry blossoms in the University of Washington’s Quad began opening on March 13, and the winter of 2015 was warm, so they may be opening earlier than that. While it is possible you are seeing flowering ornamental cherries (Prunus species), they are easily confused with their cousins in the same genus, flowering ornamental plums–extremely common street trees in Seattle–most of which are definitely flowering now. Ornamental pears (Pyrus) are also flowering now. They have white petals, and might be mistaken for cherry trees as well but the distinctive odor of pear blossoms is a big clue to their true identity: acrid, astringent, and just plain stinky!
The Vancouver Cherry Blossom Festival offers some pointers on how to tell the difference between cherry and plum blossoms. Most cherry blossoms aren’t noticeably fragrant, while plum blossoms are fragrant. Cherry blossoms usually have small splits or indentations at the ends of their petals. Note, however, that the book Japanese Flowering Cherries by Wybe Kuitert (Timber Press, 1999) says cherry “petals are mostly [emphasis mine] retuse,” that is, not all of them have a shallow notch or split on the ends of the petals.
Project BudBurst, a citizen-science phenology project, offers this distinction: apple blossoms have 3 to 5 styles whereas cherries have one. And what is a style? It is the part of the pistil between the stigma and the ovary. Brooklyn Botanic Garden also has a helpful guide to flowering trees that are not cherries.
According to the British Natural History Museum, one unifying characteristic of cherries is “flowers in clusters with stalks all arising from a central point, or arranged along a short stem, or in spikes.”