Average Temperature1 Wetting Period (hr)2 Incubation
Period (days)3
F C
79 26 11.3 ---
77 25 8 ---
75 24 6.1 ---
73-63 23-17 6 9-10
61 16 6.1 9-10
59-57 14-15 7 12-13
55 13 8 14
54 12 8.3 14
52 11 9 15
50 10 11 16
48 9 12.2 17
46 8 13.4 17
44 7 15.4 17
43 6 18 17
40 5 21.2 ---
39 4 27.8 ---
37 3 29.6 ---
35 2 34.7 ---
34 1 40.5 ---
1Average temperature during the wetting period in Fahrenheit or Celsius
2Minimum wetting period needed to achieve infection
3Time in days until visible symptoms appear