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
55.0
46
39
79
63
56
February
63.4
52
70
57
75
66
March
70.6
65
85
53
84
79
April
62.3
70
56
66
76
May
41.3
31
38
43
61
June
0
0
0
0
July
73.1
88
48
75
93
August
60.4
62
55
61
40
September
58.8
96
35
54
42
October
61.7
52
75
55
63
November
67.5
45
64
42
91
December
0
0
0
0
Average
61.8
57.9
62.3
53.6
63.0
69.3
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
-23.9
-20
-18
-27
-24
-28
February
-23.4
-19
-25
-28
-34
-32
March
-18.1
-21
-17
-18
-25
-17
April
-13.7
-17
-13
-14
-8
May
-2.7
0
-1
-3
-2
June
9.6
13
11
8
11
July
15.5
20
14
14
10
August
9.6
13
12
7
8
September
4.8
4
6
-1
2
October
-3.2
-2
-3
-5
-4
November
-11.1
-8
-9
-18
-14
December
-18.0
-16
-11
-26
-20
Average
-8.4
-20.0
-5.1
-6.8
-11.7
-8.2
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.