Table 1. The significant (p < 0.05) polynomial terms and lag effects periods tested by polynomial distributed lag model.

Variable	Polynomial terms	Lag effects terms
Mavhmd	mavhmd**1,mavhmd**2	mavhmd(1),mavhmd(2),mavhmd(3)
Avtemp	avtemp**1,avtemp**2,avtemp**3,avtemp**4	avtemp(1),avtemp(2),avtemp(3)
Devtemp	devtemp**1,devtemp**2	devtemp(1),devtemp(2)
Hsun	hsun**2	-

X**n stands for high order terms of climate factors. X(n) stands for detecting weeks of lag periods in climate factors.