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
47.2
32
35
30
65
38
February
64.5
54
71
64
67
61
March
68.0
61
82
58
70
74
April
67.7
70
72
74
71
May
35.8
36
37
19
43
June
0
0
0
0
July
66.4
82
19
79
100
August
51.4
55
53
50
37
September
48.9
57
26
55
37
October
64.5
57
80
45
61
November
71.4
41
82
71
73
December
0
0
0
0
Average
58.3
55.9
60.2
54.8
57.7
58.3
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
-22.6
-19
-19
-26
-22
-27
February
-23.6
-20
-25
-26
-31
-31
March
-18.3
-22
-17
-19
-22
-17
April
-13.6
-18
-13
-12
-9
May
-2.1
0
-2
-3
-3
June
7.1
10
9
8
8
July
13.4
17
10
14
9
August
9.0
13
11
7
10
September
4.7
6
4
3
3
October
-3.2
-2
-3
-4
-3
November
-11.6
-8
-9
-15
-10
December
-18.2
-17
-12
-23
-19
Average
-8.3
-21.5
-5.1
-7.9
-9.8
-8.6
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.