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
48.4
26
39
35
65
75
February
67.3
60
62
64
78
88
March
63.3
56
72
43
66
71
April
58.4
51
49
76
68
May
35.1
26
36
28
39
June
0
0
0
0
July
51.8
25
73
46
August
42.9
36
37
60
9
September
46.6
33
7
43
8
October
65.1
60
73
45
71
November
69.7
60
74
57
70
December
0
0
0
0
Average
54.9
53.7
47.8
48.0
58.6
52.3
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
-20.3
-16
-16
-23
-22
-25
February
-19.7
0
-24
-25
-28
-27
March
-15.9
-7
-15
-17
-20
-15
April
-10.0
-14
-11
-10
-7
May
-1.2
0
0
-1
-2
June
4.2
2
6
6
2
July
9.8
4
11
9
August
6.4
6
7
8
3
September
3.6
3
3
3
3
October
-3.5
-1
-4
-3
-4
November
-9.2
-6
-8
-12
-8
December
-16.9
-15
-11
-18
-18
Average
-7.5
-8.3
-8.1
-7.0
-8.9
-10.7
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.