. Author manuscript; available in PMC: 2015 Mar 1.

Published in final edited form as: Acta Biotheor. 2014 Jan 20;62(1):69–90. doi: 10.1007/s10441-014-9209-9

Table 1.

Summary of degree-day calculation methods. A summary of the performance of the daily average, single triangle, and single sine methods used to calculate degree-days, given different relative positions of the thresholds and the daily temperature extremes (with table quadrants corresponding to quadrants Q1–Q4 in Figure 5b). Methods shown in bold indicate the best method for the given quadrant.

δ_max > T_maxδ_min < T_min (Q2)	δ_max > T_maxδ_min > T_min(Q1)
Average: generally accurate	Average: slight underestimates
Triangle: generally accurate	Triangle: strong underestimates, strong overestimates
Sine: strong underestimates, strong overestimates	Sine: slight underestimates, (strong δ_min close to T_min)
δ_max < T_maxδ_min < T_min (Q3)	δ_max < T_maxδ_min > T_min (Q4)
Average: generally accurate, (slight δ_max close to T_max)	Average: slight underestimates, slight overestimates
Triangle: strong underestimates, strong overestimates	Triangle: strong underestimates, strong overestimates
Sine: strong underestimates	Sine: slight underestimates