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
80.7
65
53
66
92
90
February
75.4
65
68
87
76
75
March
74.6
70
58
79
70
83
April
83.6
82
83
77
74
May
83.6
81
74
94
95
June
85.3
86
100
96
56
July
91.5
90
91
95
87
August
89.6
85
84
91
90
September
89.3
86
90
94
87
October
84.2
86
81
89
78
November
82.0
72
72
86
86
December
68.4
49
58
38
88
Average
82.1
67.2
78.3
81.3
85.9
85.1
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
-17.6
-14
-12
-17
-14
-21
February
-15.4
-11
-15
-19
-17
-22
March
-10.2
-11
-10
-10
-12
-10
April
-3.0
-10
-3
-7
1
May
8.0
6
7
8
10
June
16.7
15
17
17
16
July
18.6
19
18
17
17
August
15.3
17
14
14
17
September
10.2
10
11
9
9
October
0.9
0
0
0
1
November
-10.8
-6
-7
-19
-9
December
-11.9
-6
-10
-6
-13
Average
-1.1
-12.0
1.2
0.4
-1.3
-1.8
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.