Spring Has Sprung by USGS Vizlab

Is it spring yet? New green plant growth is one of the first indicators of spring and the end of cold winter months. To celebrate the changing seasons in the United States, the United States Geological Survey (USGS) VizLab created this fully reproducible animation of the timing of spring onset. The animation uses open data and was made entirely in R, namely using the ggplot2, cowplot, showtext, geomtextpath, and rnpn packages.

We developed this visualization by animating the “Spring First Leaf Index” from the USA National Phenology Network. The Spring First Leaf Index represents when leaves first appear (called "leaf out") on two early blooming woody plants: lilacs and honeysuckles. We used daily Spring First Leaf Index data from January 2023 through April 2nd (when the visualization was published) to show when and where the country was first experiencing spring conditions. As the animation progresses from January to April, a histogram and map update synchronously to show the total land area “entering spring.” The color scale is coordinated between the chart and the map, enabling the audience to see spatio-temporal patterns in spring timing at two-week intervals. Data for the current year are shown in comparison to the 30-year mean timing of spring leaf out.