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
52.2
41
44
33
54
84
February
71.3
60
77
68
78
89
March
65.5
69
81
60
68
70
April
58.1
61
53
71
67
May
33.6
34
46
23
35
June
0
0
0
0
July
57.3
48
19
77
87
August
47.0
53
48
61
32
September
45.9
57
29
44
41
October
67.2
74
80
44
66
November
66.6
50
88
55
55
December
0
0
0
0
Average
56.5
63.2
60.2
53.6
57.1
56.6
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
-19.2
-17
-19
-21
-23
-20
February
-17.8
-20
-18
-17
-17
-14
March
-15.3
-15
-16
-15
-19
-12
April
-11.9
-18
-8
-9
-7
May
-1.0
-2
-2
0
0
June
5.2
7
6
7
5
July
11.6
14
8
13
7
August
8.2
11
9
8
8
September
3.9
4
3
3
3
October
-3.0
-3
-3
-4
-4
November
-10.1
-7
-10
-14
-9
December
-17.0
-18
-13
-20
-19
Average
-7.5
-18.8
-6.5
-5.0
-7.9
-6.9
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.