ABCDEFGHIJKLMNOPQRSTUVWXYZ
1
ZoneMin temperature °C (L)Min temperature °C (H)Avg last frost date (L)Avg last frost date (H)Avg first frost date (L)Avg first frost date (H)
2
0a< −53.9
3
0b−53.9−51.1
4
1a−51.1−48.3May 22June 4August 25August 31
5
1b−48.3−45.6May 22June 4August 25August 31
6
2a−45.6−42.8May 15May 22September 1September 8
7
2b−42.8−40May 15May 22September 1September 8
8
3a−40−37.2May 1May 16September 8September 15
9
3b−37.2−34.4May 1May 16September 8September 15
10
4a−34.4−31.7April 24May 12September 21October 7
11
4b−31.7−28.9April 24May 12September 21October 7
12
5a−28.9−26.1April 7April 30October 13October 21
13
5b−26.1−23.3April 7April 30October 13October 21
14
6a−23.3−20.6April 1April 21October 17October 31
15
6b−20.6−17.8April 1April 21October 17October 31
16
7a−17.8−15March 22April 3October 29November 15
17
7b−15−12.2March 22April 3October 29November 15
18
8a−12.2−9.4March 13March 28November 7November 28
19
8b−9.4−6.7March 13March 28November 7November 28
20
9a−6.7−3.9February 6February 28November 25December 13
21
9b−3.9−1.1February 6February 28November 25December 13
22
10a−1.11.7No frostNo frostNo frostNo frost
23
10b1.74.4No frostNo frostNo frostNo frost
24
11a4.47.2No frostNo frostNo frostNo frost
25
11b7.210No frostNo frostNo frostNo frost
26
12a1012.8No frostNo frostNo frostNo frost
27
12b<12.8No frostNo frostNo frostNo frost
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100