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
68.0
60
66
49
79
87
February
70.3
53
88
62
68
75
March
70.4
58
83
73
67
74
April
72.8
63
75
59
69
May
76.6
82
65
81
77
June
79.6
76
80
87
54
July
79.5
79
91
63
49
August
80.8
93
91
87
48
September
75.6
84
81
48
52
October
73.7
82
71
66
57
November
74.9
59
78
76
76
December
70.1
66
63
77
67
Average
73.4
56.6
77.7
75.8
71.0
63.3
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
-20.4
-18
-11
-24
-18
-18
February
-24.0
-21
-29
-27
-21
-23
March
-17.5
-17
-20
-17
-16
-18
April
-9.1
-8
-10
-8
-10
May
0.2
7
0
-1
-2
June
8.5
13
9
9
7
July
16.0
15
17
17
14
August
14.7
16
16
14
15
September
8.5
11
10
8
7
October
1.1
3
3
4
-1
November
-10.8
-7
0
-5
-12
December
-16.6
-11
0
-19
-17
Average
-6.5
-19.4
-2.4
-2.1
-3.0
-5.1
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.