December 2021

This Environmental Protection Agency report discusses how climate change affects the timing and nature of seasonal events, summarizes changes that have been observed in the United States, and describes the implications of these changes. The main report discusses the science behind seasonal events and the ways in which climate change can influence seasonal trends. It uses many years of observations from EPA’s climate change indicators to explore the interconnectedness of seasonal changes. The technical appendix describes EPA's evaluation approach and criteria for selecting indicators, and it also provides documentation of sources and methods for the indicators featured in this report. 

Report Cover of the December 2021 EPA Seasonality and Climate Change Report
Vulnerability Assessments
Climate Impacts