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
69.9
76
63
60
80
69
February
72.4
71
92
60
68
68
March
78.6
62
85
82
78
83
April
81.6
77
88
81
80
May
81.1
81
79
80
83
June
91.6
91
97
96
82
July
96.4
100
100
96
96
August
94.0
96
100
94
90
September
86.7
84
87
75
87
October
77.4
76
76
72
88
November
81.2
71
75
78
88
December
80.6
75
76
94
73
Average
82.6
67.8
85.0
84.9
83.5
83.7
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
-25.1
-24
-23
-28
-22
-23
February
-29.8
-25
-34
-31
-25
-28
March
-21.2
-21
-23
-20
-22
-21
April
-13.8
-10
-13
-11
-13
May
-2.6
6
-1
-2
-4
June
11.3
14
14
10
11
July
18.2
20
20
17
18
August
16.0
18
16
15
18
September
8.0
10
9
9
7
October
-2.7
2
0
3
-2
November
-15.3
-11
-17
-10
-16
December
-22.6
-15
-22
-23
-23
Average
-8.0
-24.8
-4.2
-6.7
-5.0
-7.6
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.