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
28.3
12
0
0
57
February
20.6
0
0
0
31
March
18.8
0
0
0
47
April
22.6
0
0
68
May
29.6
0
0
71
June
53.2
0
91
July
84.9
97
49
94
August
92.4
92
90
90
99
September
89.6
90
94
90
86
October
80.9
81
80
70
93
November
69.8
74
56
70
79
December
47.6
57
52
36
51
Average
46.9
3.9
50.9
33.6
69.8
82.9
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
-10.9
-11
-10
-8
-9
February
-9.1
-8
-9
-10
-11
March
-6.2
-6
-8
-6
-6
April
-2.1
-3
-2
-2
May
2.3
3
3
2
June
10.0
10
11
July
12.1
14
12
12
August
11.5
12
11
12
14
September
8.6
8
10
10
9
October
1.4
2
1
1
3
November
-5.8
-4
-7
-3
-3
December
-8.1
-8
-9
-7
-8
Average
-1.5
-9.8
-2.9
0.5
0.9
2.8
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.