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
63.5
58
58
55
59
69
February
68.2
74
68
57
56
80
March
63.3
60
58
56
66
70
April
72.0
59
79
81
70
May
75.7
69
69
80
78
June
84.0
90
89
62
89
July
80.1
66
88
81
86
August
82.7
83
78
74
85
September
82.9
75
69
90
91
October
77.3
69
77
77
77
November
72.7
53
65
84
70
December
61.9
58
53
57
51
Average
74.4
60.8
68.2
70.3
73.4
78.8
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
-17
-19
-22
-16
-20
February
-24.8
-16
-27
-26
-17
-23
March
-15.1
-12
-15
-15
-18
-17
April
-8.3
-6
-8
-6
-9
May
1.0
3
2
1
0
June
10.8
13
16
6
12
July
15.9
17
18
13
19
August
14.1
16
13
13
16
September
9.3
10
10
11
9
October
2.2
3
3
6
0
November
-6.0
-4
-7
-4
-6
December
-12.3
-8
-10
-11
-12
Average
-5.8
-15.3
-2.8
-3.0
-2.2
-3.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.