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
54.8
64
27
39
52
78
February
58.3
27
61
59
67
76
March
63.4
58
76
43
69
69
April
60.0
53
55
80
58
May
36.7
24
37
27
48
June
0
0
0
0
July
77.3
84
42
89
85
August
52.7
53
49
63
40
September
55.5
53
42
60
51
October
66.6
52
75
73
58
November
68.2
38
77
66
75
December
0
0
0
0
Average
57.4
46.3
52.3
51.6
64.0
57.2
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
-20.1
-19
-19
-25
-20
-24
February
-22.7
-19
-27
-27
-28
-30
March
-17.7
-19
-15
-18
-20
-15
April
-12.5
-16
-13
-11
-7
May
-1.3
1
-1
-3
-1
June
10.3
11
11
10
10
July
14.9
19
13
15
11
August
9.8
12
10
8
11
September
5.3
6
6
4
4
October
-3.3
-2
-3
-5
-3
November
-10.6
-8
-7
-15
-10
December
-17.8
-14
-10
-21
-19
Average
-8.6
-19.0
-4.5
-5.0
-7.0
-6.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.