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
75.4
71
81
69
69
77
February
81.9
76
98
71
85
86
March
74.1
82
80
73
82
64
April
81.8
91
86
83
75
May
79.2
86
85
77
75
June
94.1
89
100
100
100
July
92.3
92
96
89
87
August
93.0
88
96
95
92
September
84.9
75
74
76
90
October
78.5
70
80
62
81
November
79.5
75
81
97
81
December
75.0
78
70
68
76
Average
81.7
77.4
83.2
81.3
81.3
80.9
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
-27.6
-24
-28
-28
-21
-25
February
-30.4
-27
-35
-31
-23
-31
March
-23.5
-20
-20
-22
-24
-25
April
-15.5
-12
-15
-12
-15
May
-4.5
-1
-3
-3
-6
June
6.7
7
9
5
7
July
12.3
14
14
10
13
August
10.1
11
11
8
11
September
3.7
4
4
3
4
October
-4.3
-2
-4
0
-4
November
-16.8
-9
-19
-11
-17
December
-21.3
-17
-19
-21
-20
Average
-11.5
-24.5
-7.2
-9.3
-8.3
-9.2
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.