For me, February is always the longest month, even though it has the fewest number of calendar days. It’s the month when winter has gone on long enough and I’m just done with it. It’s the month I start looking for Spring. So – will it be early this year?
According to Punxatawney Phil, the answer is YES. On February 2, the groundhog did NOT see his shadow, predicting an early spring. His prediction is backed up, for parts of the country anyway, by the National Phenology Network’s 2019 map of accumulated growing degree days. Here’s what Nature’s Notebook observers are reporting on plants and animals across the country. The orange areas are warming up faster, blue areas are warming up more slowly, and tan areas show no change either way.
Here’s NPN’s forecast as of February 18 showing Spring leaf out spreading north through Southwest and Southeast states. Spring is 15 days early in Nashville, TN and 6 days early in Norfolk, VA. Long-term forecasts indicate that spring leaf out may arrive earlier than average (1982-2010) in many parts of the western US and Northeast and later than average in parts of the western US and the Southeast.
To see how things progress over time, visit the National Phenology Network here.
What’s Phenology and What Does It Do For Us?
Phenology is the study of recurring plant and animal life cycles. It helps us understand the temperatures and climate conditions plants need to begin growing each Spring. The National Phenology Network’s “spring indices” based on information about the accumulated warmth required for native and cultivated plants to leave dormancy and begin to grow. Using this information they’ve developed a set of algorithms (think fancy math like what Google uses to figure out what you’re looking for) that can use the data from any weather station to tell us when spring, or plant growth begins.
The origin of the US National Phenology Network is work done by Bozeman, Montana Professor Joseph Caprio who created the “Lilac Network” about 70 years ago. Lilacs bloom in early spring, so they’re a good indicator of when spring has sprung. Caprio enlisted citizens across Montana to send in their observations of lilac bloom dates and temperatures. By the 1980s, the network had spread nationwide, and ultimately became the National Phenology Network. Based in part on decades of lilac data, as well as lots of other information gathered by citizens who signed up to monitor temperatures and provide observations on plants and animals, we now know Spring is coming 6.8 days earlier than it did in the midwest in the 1950s when Caprio began his observations. We also know that spring is showing up later and later every year in the south.
You can see the trends here:
The years 2012 and 2017 stand out. Spring 2012 was the earliest on record. Here it is compared to 2017.
An early spring means changes to how we plan for pasture improvements and how we manage grazing. It can also give us an idea of what kind of summer we might have.
In the meantime, only 10 more days of February, and we’re on to March and the promise of spring breezes!
Thanks for reading!
Kathy
