The end of the US growing season is when satellites see the overall greenness of foliage start to decline.
This shows a trend for end of growing season 9 days later over 36 years.
Concord MA, starting with Thoreau journals ~1850, and Boston MA
from Polgar, C.A, R.B Primack, E. Williams, S. Stichter, and C. Hitchcock. 2013. "The effect of temperature on the timing of the adult flight period of Lycenid butterflies in Massachusetts." Biological Conservation 160: 25-31
England, from Amano et al. (2010).
From IPCC, 2007. Many-species studies found (averages of range endpoints used) 0.8, 1.6, 4.5, 2.5, 2.85, 4.4, 3.1, 3.15, 6.3, and 0.45 days per decade earlier blooms or arrivals. Grand average of these is 3.0 days per decade earlier.
Section Map: Bio Impacts