Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 5 mi or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.
Marginal VFR conditions (%)
Month
Average
2024
2023
2022
2021
2020
January
64.3
54
62
46
72
71
February
64.7
53
59
61
64
62
March
67.7
56
70
70
75
73
April
74.6
70
82
68
69
May
76.2
77
84
73
79
June
89.2
83
93
94
88
July
90.9
89
94
91
86
August
86.9
92
96
85
83
September
74.9
72
73
56
83
October
73.6
80
74
57
87
November
68.3
57
71
65
82
December
59.6
59
39
63
48
Average
74.4
54.6
75.4
78.5
74.1
78.1
Marginal VFR conditions or better during daylight period
Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 3⅛ mi or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.
Maximum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-24.7
-19
-22
-27
-18
-22
February
-28.3
-24
-33
-31
-23
-27
March
-20.8
-18
-21
-20
-20
-20
April
-11.0
-10
-11
-10
-12
May
-2.7
4
0
-2
-4
June
9.3
11
12
9
9
July
16.2
17
18
15
16
August
14.0
16
15
13
15
September
7.5
9
9
7
7
October
-1.5
2
0
3
-2
November
-13.1
-9
-14
-8
-15
December
-20.9
-12
-20
-19
-20
Average
-8.6
-21.5
-4.2
-6.8
-5.6
-7.8
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.