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
72.2
53
54
61
78
68
February
80.0
86
64
72
92
74
March
75.9
62
66
68
73
78
April
74.8
55
55
87
70
May
72.6
73
70
81
75
June
72.9
82
82
57
84
July
63.9
37
39
67
81
August
66.3
100
37
65
81
September
75.8
87
67
84
79
October
83.8
69
83
74
91
November
79.6
64
64
90
81
December
75.0
65
72
73
87
Average
73.4
68.4
68.0
68.4
77.3
79.2
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
-19.7
-15
-23
-21
-13
-17
February
-19.0
-13
-23
-24
-16
-18
March
-12.0
-9
-12
-11
-12
-13
April
-5.2
-4
-5
-1
-6
May
2.8
6
5
4
0
June
11.0
16
16
6
12
July
14.3
16
5
14
19
August
13.7
20
11
13
16
September
10.1
13
12
12
10
October
5.0
8
6
10
2
November
-4.2
-3
-4
-1
-4
December
-11.6
-7
-9
-10
-11
Average
-3.5
-13.0
1.2
-3.9
0.1
-1.4
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.