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
74.3
76
68
64
59
80
February
71.8
65
87
65
65
66
March
78.2
80
68
66
86
83
April
82.0
83
81
76
90
May
77.5
72
73
68
65
June
71.8
78
97
47
79
July
74.5
55
91
66
76
August
77.2
85
87
55
80
September
83.0
75
66
89
88
October
83.0
72
80
73
81
November
84.3
79
92
94
63
December
74.6
78
66
87
67
Average
77.3
75.0
74.1
75.4
72.5
76.9
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
-21.4
-16
-21
-24
-16
-21
February
-24.6
-23
-28
-25
-18
-24
March
-16.1
-12
-14
-16
-19
-18
April
-10.9
-6
-9
-8
-10
May
-2.1
0
-1
-2
-3
June
4.8
6
9
2
5
July
10.2
11
14
8
13
August
9.7
11
10
8
11
September
5.6
8
6
7
6
October
0.8
2
1
5
-1
November
-6.1
-4
-7
-4
-7
December
-13.8
-9
-10
-12
-12
Average
-7.0
-17.7
-6.7
-7.2
-5.2
-5.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.