Oak trees will produce a larger crop of acorns during wet years. Like many of the other weatherlore, a wet year sometime precedes a harsh winter. So a likely correlation could be made.. but I have no science to back that up. Squirrels gathering nuts furiously could indicate that the squirrels sense a pressure drop, and are preparing for a storm. There is limited science to be found on this topic, but it seems to be one of the favorites.
2. Wooly Bear Caterpillar
Many Ashevillewx readers chimed in about the use of the Wooly Bear Caterpillar, and the burnt orange band thats present on its coat. There is actually a festival held every year in Vermilion, Ohio where a local weatherman come and reads the wooly worms. How awesome is that? They also celebrate the Woolly Worm in Banner Elk, NC! So, if you believe this weatherlore, you are not alone! The story goes, that apparently however long the burnt orange stripe is, indicates how long winter will last. The dark bands in the stripe can also be used to signify when snows will occur. I love the concept, but it seems a little farfetched.. so lets see if there is any science behind the method.
Heres an except taken from weather.gov
“The woolly bear caterpillar's coloring is based on how long caterpillar has been feeding, its age, and species. The better the growing season is the bigger it will grow. This results in narrower red-orange bands in its middle. Thus, the width of the banding is an indicator of the current or past season's growth rather than an indicator of the severity of the upcoming winter. Also, the coloring indicates the age of the woolly bear caterpillar.”
As far as the story about the woolly caterpillar's coat, this is how Mother Nature helps it survive winter. The fur is called setae and it isn't there to protect them from the cold weather. Instead it actually helps them to freeze more controllably. Here is something truly remarkable. Once settled in, the caterpillars hibernate, creating a natural organic antifreeze called glycerol. They freeze bit by bit, until everything but the interior of their cells are frozen. These interior cells are protected by the hemolymph. Woollybears can - and do - survive to temperatures as low as -90oF. This ability to adapt to cold shows up particularly in the Arctic, where the woolly worms live in a strange state of slow motion. Most caterpillars live for two to four weeks before becoming moths. The Arctic woolly worms, however, spend at least 14 years in the process! The woolly bear caterpillar has even been known to survive an entire winter completely frozen in an ice cube.
Interesting right? So, wooly worms are a better predictor of how the past season was, compared to how the future season will be. But, its still really fascinating to learn that they can live in temps as low as -90 degrees!