Across wide swaths of the United States, spring has arrived two to three weeks earlier than normal, with temperatures hovering well above average and plants already budding, according to data from the U.S. Geological Survey.
As Vox reports, for almost the entire U.S. West Coast, Southwest, and mid-South — including Washington, D.C., where temperatures hit 80 degrees Fahrenheit on February 21 — spring has arrived as much as 22 days earlier than the 50-year average. Spring in the U.S. Southeast, in contrast, is arriving a few days later than normal due to abnormally cool temperatures. The USGS data is compiled by the National Phenology Network, a collaborative initiative that maps the timing of seasonal events through temperature trends and plant activity.
The early spring arrival coincides with a slew of other odd weather trends happening across the globe, from a heat wave in the Arctic, where temperatures reached 43 degrees Fahrenheit in February, to a cold snap in Europe.
An early spring comes with consequences: Disease-carriers such as ticks and mosquitos emerge sooner, the USGS warns, and it can trigger a longer, more intense pollen season. In addition, if flowers bloom earlier than normal, it “can disrupt the critically important link between wildflowers and the arrival of birds, bees, and butterflies” that is critical to the pollination of crops and other plants, the USGS wrote.
For more on how global warming is changing the jet stream and altering weather patterns in the Northern Hemisphere, click here to read Yale e360’s interview with atmospheric scientist Jennifer Francis.