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
68.7
70
83
0
83
February
59.8
51
64
62
March
48.4
58
33
73
55
April
56.8
76
73
51
May
55.3
61
46
89
June
64.0
80
56
0
71
July
46.9
37
100
52
August
47.2
45
54
September
66.4
61
50
77
77
October
76.5
86
50
62
75
November
70.2
58
90
0
December
61.9
67
44
17
Average
52.8
58.7
61.4
62.1
67.6
66.8
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
-12.7
-9
-15
-11
-17
February
-9.7
-7
-10
-13
March
-5.1
-5
-6
-4
-7
April
0.2
-5
0
2
May
9.8
7
7
13
June
15.4
14
11
5
15
July
15.6
15
15
14
August
14.3
14
15
September
8.4
9
6
6
10
October
3.1
3
4
2
5
November
-6.3
-2
-11
-7
December
-10.7
-12
-7
-10
Average
-1.7
-7.2
4.7
-3.9
-4.4
3.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.