KMSP - Despite what the thermometer has said as of late, it is not time for spring… although many parts of the U.S. are already beginning to leap into the warm season, even though the calendar still reads winter. An unusually warm stretch of weather across much of the U.S. has led to some spring-like changes happening before March even begins. Lilacs are blooming in the Southwest, flowers and trees are greening up in the southeast, and some buds on the cherry trees in DC have already been spotted… all are weeks ahead of schedule.
While many of us pray every year for an early spring, warm temperatures in February and March can often do more harm than good when it comes to everything from allergy symptoms to bird migrations to food prices. An early spring bloom can mean a longer and more severe pollen season… not good for the tens of millions that suffer from seasonal allergies. Crops that bloom early have a much higher likelihood of getting damaged or destroyed by a late season frost, drought, or severe weather. Even the early bloom of seasonal flowers can disrupt the important relationship they have with the arrival of birds, bees, and butterflies. Not to mention, the longer the growing season, the longer the pesky mosquitoes hang around. See…. Maybe an early spring isn’t all it’s cracked up to be.
The map that shows us how far along we are into the spring bloom is put together by researchers at the US Geological Survey (USGS) and the National Phenology Network (NPN). They use temperature data from the National Oceanic and Atmospheric Administration (NOAA) along with the National Weather Service, and add it to maps based on model data collected by the NPN that uses field observations collected on sensitive blooming plants to see if they’ve bloomed. The most sensitive of these plants are lilacs and honeysuckles… plants that are extremely sensitive to varying temperatures. When pollen levels get high enough and these plants are in bloom, then that area is considered to be in spring condition and is added to the map in the color representing how ahead or behind average that spot is with its spring bloom. The map above is what you get.
Any red areas indicate that the spring bloom is ahead of average and blues indicate a later than normal spring bloom. Right now, much of the southeast and parts of the Mid Atlantic are some 3+ weeks ahead of schedule, while southern Arizona and the LA basin are behind the average by a few days. For Minnesota, our spring bloom doesn’t typically begin until the last half of April with a drastic increase in tree and grass pollen that helps flowers bloom across the area. It then takes about 3 to 4 weeks before vegetation has fully grown in. Last season, we saw our spring bloom begin a good 2 weeks early with buds on the trees and extremely high pollen counts by the first of April.