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
71.0
62
66
83
72
61
February
81.8
71
73
91
84
84
March
84.9
90
85
71
83
85
April
87.0
76
95
83
90
May
92.2
90
92
97
86
June
92.6
97
99
84
97
July
88.6
55
92
100
91
August
90.4
77
93
94
94
September
84.8
66
93
75
91
October
70.4
62
82
68
71
November
69.3
54
70
67
79
December
75.9
69
86
83
77
Average
84.0
74.7
73.2
87.7
84.4
86.6
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
-23.7
-26
-17
-27
-20
-24
February
-23.2
-18
-25
-26
-26
-23
March
-15.6
-14
-15
-15
-17
-16
April
-5.3
0
-4
-7
-6
May
7.7
17
9
5
3
June
17.4
19
21
17
16
July
20.8
24
21
21
20
August
18.0
19
20
18
18
September
10.2
13
12
10
9
October
0.1
4
1
3
-2
November
-13.2
-10
-11
-11
-14
December
-21.7
-14
-23
-25
-21
Average
-4.1
-20.8
1.3
-2.9
-3.4
-4.7
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.