Growing up in rural Southwestern PA I ended up learning a lot of different things about country living. I learned to tell the difference between summer butter and winter butter, the names of different wildflowers and a lot of country expressions and seasonal weather lore. One county expression that I heard a lot at this time of year was "dogwood winter". The beautiful dogwood trees would bloom and then we would get a few days of cold weather. That's dogwood winter. After doing some research it turns out that this saying is credited to rural Appalachia folk. (Where I grew up is 40 miles from Morgantown, West Virginia and 40 miles from Pittsburgh). That's what kind of weather we are having now. You won't hear any complaints from me. I love cool weather.
Here and here are some tidbits about this bit of weather lore.