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
66.0
63
71
86
0
85
February
85.2
79
93
78
100
94
March
90.9
88
89
89
100
95
April
92.6
91
83
98
May
95.5
96
91
98
June
71.2
70
100
100
95
July
88.7
93
85
August
68.2
93
67
9
September
59.4
20
94
0
October
72.4
91
97
85
0
November
74.4
89
88
94
0
December
65.0
68
74
76
0
Average
79.6
77.6
80.4
86.6
76.0
53.4
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
-10.5
-8
-8
-13
-6
-9
February
-8.4
-1
-6
-13
-3
-7
March
-1.1
0
-3
-2
0
1
April
5.2
4
3
5
May
15.5
19
14
15
June
21.6
24
17
21
22
July
24.3
23
25
August
22.7
22
20
24
September
17.7
20
20
17
October
8.7
10
8
13
6
November
-1.6
2
1
2
2
December
-6.1
0
-7
-6
-4
Average
4.9
-3.0
9.1
-1.3
5.3
7.7
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.