Table 5. Fifty-six-year trends (1953–2008) in growing season length, first autumn frost, last spring frost, and growing degree days.

Site	Growing season length(days/decade)	Last spring frost(days/decade)	First Autumn Frost(days/decade)	Growing degree days(GDD/decade)
NOAA	−0.68	0.41	−0.28	−5.83
A1	−0.44	−0.80	−1.24	13.31
B1	−0.90	−0.20	−1.11	35.21**
C1	−4.37**	1.51	−2.86**	33.49**
D1	−0.62	0.31	−0.31	15.38**

Rates of change (slopes) were derived from linear regression.

^**p<0.01,

^*p<0.05.