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
87.2
84
82
84
91
97
February
92.3
94
91
83
96
96
March
90.2
96
85
86
97
91
April
86.8
84
88
84
89
May
78.5
72
72
86
88
June
0
0
0
0
July
71.5
56
63
74
75
August
75.6
69
71
68
72
September
88.6
82
81
96
98
October
88.7
88
84
88
91
November
87.8
90
91
91
88
December
87.5
97
82
81
90
Average
85.0
92.8
77.9
78.6
85.6
87.0
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
-22.4
-19
-25
-20
-16
-24
February
-24.6
-19
-28
-25
-20
-26
March
-20.3
-21
-18
-19
-20
-20
April
-12.6
-11
-13
-9
-10
May
-3.3
-3
-4
-1
-3
June
4.2
6
4
4
4
July
7.1
5
6
8
9
August
7.7
9
7
7
9
September
3.6
3
5
3
4
October
-1.6
-1
-2
3
-1
November
-8.8
-3
-13
-6
-6
December
-13.0
-13
-9
-13
-13
Average
-8.0
-20.5
-7.4
-7.4
-6.9
-7.6
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.