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
70.8
87
56
68
86
77
February
71.9
67
73
55
72
77
March
76.8
74
87
70
84
69
April
78.6
64
87
70
93
May
74.5
61
85
68
78
June
0
0
0
0
July
96.7
100
97
94
91
August
86.2
84
93
81
92
September
57.8
55
49
48
61
October
67.2
62
57
59
79
November
68.5
55
74
60
66
December
0
0
0
0
Average
74.7
72.4
69.8
73.1
70.5
79.1
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
-27.4
-26
-28
-28
-24
-27
February
-29.0
-25
-32
-31
-30
-30
March
-25.7
-23
-27
-22
-26
-27
April
-17.7
-14
-16
-17
-16
May
-5.8
-1
-4
-5
-5
June
6.5
8
7
5
7
July
13.7
16
16
10
16
August
11.2
12
12
9
12
September
2.9
5
3
4
3
October
-5.6
-1
-6
-1
-4
November
-17.8
-13
-18
-13
-16
December
-23.1
-17
-26
-26
-22
Average
-11.0
-25.3
-8.4
-9.3
-10.6
-10.9
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.