Seasonal Changes in the United States (1948–2012)

In climatological research, seasons are often discussed as static, monthly segments without consideration of spatial or temporal variability. However, as best illustrated by the 2013 -2014 winter, seasons are not the same across time or space. Using various metrics to define seasons including 10-day running averages of apparent temperature and clustered synoptic-scale map patterns, this research considers seasonal variability and investigates long-term changes (1948- 2012) across the U.S. Despite the different methodological approaches, results indicate significant changes in seasonal start date and length. Summer and spring both begin earlier while autumn and winter begin later in the year. Seasonal variability and change influences a range of environmental processes including agricultural maturation and human acclimatization to extreme temperature environments. The presented research serves as a challenge to the traditional use of seasons in climatology, and the results draws attention to the need for diverse, regional approaches to addressing climate change issues.