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
65.0
60
54
78
57
56
February
80.1
85
76
67
86
85
March
84.8
79
72
78
93
88
April
81.1
70
68
77
93
May
90.8
88
91
91
94
June
91.8
87
91
95
97
July
90.9
91
87
85
92
August
86.3
86
85
83
90
September
85.4
77
84
94
93
October
86.0
83
93
77
92
November
78.9
86
66
94
86
December
63.5
54
59
73
66
Average
82.5
75.0
77.9
80.0
84.5
87.5
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
-8.6
-6
-6
-11
-5
-6
February
-6.7
1
-3
-10
-10
-3
March
2.0
3
0
0
7
3
April
8.1
7
5
10
9
May
18.2
21
17
19
17
June
23.7
25
23
26
24
July
25.6
24
25
27
27
August
23.6
24
24
26
24
September
19.2
21
20
21
17
October
10.1
11
13
14
6
November
1.0
3
2
2
5
December
-4.1
2
-5
-4
-3
Average
8.3
-1.4
10.8
9.1
11.3
9.9
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.