Depending on where you live, you may have noticed unseasonably warm temperatures pushing flowers and trees to bloom much earlier than usual. But for some parts of the country, spring is a little bit behind schedule.
A new set of maps from the U.S. Geological Survey shows spring is arriving one to two weeks early in parts of California and Nevada and the upper Southeast. Spring is arriving on time to two weeks early in much of the South, and a few days early in Nashville, Tennessee, and Madison, Wisconsin.
But parts of the country will be getting their spring blooms a little behind schedule this year. Spring is arriving two to three weeks late in much of Oregon and Washington and one to two weeks late across the Great Plains, southern Midwest and Mid-Atlantic. Parts of Arizona, California, Nevada and the Southern Great Plains are one to two weeks late. Spring is arriving about four days late in Boston and Detroit.
The maps are produced by the USGS-led USA National Phenology Network and are updated daily. To create them, researchers use climate change indicators called the spring indices. These are models scientists have developed to predict the start of spring based on the first leaf and first bloom of lilac and honeysuckle plants, two temperature-sensitive but otherwise common flowering plants. They applied these plant models to recent temperature data to create maps showing how this year compares to a long-term average (1982-2010).
“While these earlier springs might not seem like a big deal — and who among us doesn’t appreciate a balmy day or a break in dreary winter weather — it poses significant challenges for planning and managing important issues that affect our economy and our society,” Dr. Jake Weltzin, a USGS ecologist and the executive director of the USA-NPN, said in a 2017 statement.
Everyone likes spring, but earlier is not better
So while we're happy to toss aside the winter wear and see the first flowers bloom, there are lots of negatives to the early onset of warm weather, the USGS points out:
"Changes in the timing of spring can affect human health, bringing early-season disease-carriers such as ticks and mosquitoes, and an earlier, longer and more vigorous pollen season. And while a longer growing season can result in increased yields for some crops, it is risky because of the higher likelihood of plant damage caused by late frosts or summer drought. Even something as seemingly simple and beautiful as flowers blooming earlier can disrupt the critically important link between wildflowers and the arrival of birds, bees, and butterflies that feed on and pollinate the flowers. Such changes may prove beneficial to some plants and animals, including some harmful invasive ones, but may be detrimental to others. Changes in seasons can affect economically and culturally important outdoor recreation activities, including affecting the timing of hunting and fishing seasons."
Editor's note: This article has been updated since it was originally published in March 2017.