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
83.3
83
67
92
84
86
February
74.3
69
71
85
89
79
March
65.2
68
51
91
70
62
April
82.6
84
87
83
62
May
85.0
81
74
91
97
June
82.8
73
80
80
89
July
69.1
49
85
60
68
August
75.3
46
68
80
89
September
86.7
80
90
84
95
October
81.6
75
80
86
81
November
75.7
79
60
93
65
December
73.6
67
56
59
92
Average
77.8
71.8
68.1
79.4
79.6
80.6
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
-12.6
-10
-11
-14
-11
-16
February
-10.8
-7
-12
-11
-13
-15
March
-5.2
-6
-6
-4
-8
-5
April
-1.9
-6
2
1
0
May
10.1
8
9
12
14
June
16.1
14
17
12
17
July
16.4
15
17
14
15
August
14.2
14
13
13
16
September
10.1
9
10
9
9
October
3.1
2
2
1
4
November
-5.6
-3
-3
-13
-3
December
-9.1
-12
-3
-10
-9
Average
1.6
-8.3
0.6
2.6
0.4
2.4
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.