Did Spring Come Early This Year?

The USA National Phenology Network collects data on the effect of the seasons and the climate on animal and plant life. It observes and studies how seasonal and interannual variations in the climate affect biological life cycles. As part of this work it has created an interactive map showing where Spring in the United States has arrived early and where it has arrived later than usual.

The NPN interactive map Spring Leaf Anomalies shows where in the country Spring leaves appeared earlier or later than normal compared to the average from 1991-2020. The red areas on the map show where Spring arrived early this year and the blue areas show where Spring has arrived later than usual. 

This year low pressure in the west of the United States meant that Winter was colder and wetter than usual. Conversely a ridge of high atmospheric pressure kept the east relatively warm. These conditions have fed into the late arrival of Spring in the west and its early arrival in the east.