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
86.6
84
83
89
100
February
80.9
88
77
92
100
0
March
70.8
63
67
72
April
76.7
69
72
May
62.2
72
77
June
51.9
0
33
85
July
76.1
74
72
75
August
76.2
66
75
76
September
87.1
91
86
84
October
91.2
87
94
93
November
85.2
76
81
94
December
81.9
89
82
84
Average
79.7
75.3
77.3
75.1
79.4
100.0
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
-13.0
-13
-13
-16
-16
February
-13.4
-15
-17
-17
-20
-17
March
-10.2
-14
-10
-10
April
-3.6
-4
-5
May
2.1
2
2
June
8.0
8
8
7
July
13.5
15
12
12
August
11.5
14
11
11
September
8.8
6
9
7
October
2.1
2
2
1
November
-4.0
-3
-2
-10
December
-10.4
-15
-5
-12
Average
-4.2
-14.1
-1.3
-1.3
-1.6
-16.1
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.