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
90.1
82
96
93
92
94
February
90.6
92
96
96
85
96
March
82.7
67
77
80
91
95
April
80.7
68
79
78
93
May
77.7
79
77
67
93
June
86.1
99
91
84
94
July
83.3
56
68
99
87
August
85.2
93
90
91
86
September
83.9
86
94
70
75
October
82.2
80
87
72
90
November
86.8
81
89
87
90
December
89.5
91
87
91
94
Average
84.0
79.2
83.8
85.6
83.0
89.6
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
-20.1
-17
-21
-23
-14
-19
February
-22.0
-20
-27
-24
-14
-23
March
-16.9
-13
-13
-15
-18
-16
April
-8.0
-7
-9
-6
-8
May
-2.6
-1
-1
-1
-1
June
6.2
9
9
4
6
July
11.5
8
10
13
15
August
10.9
12
11
11
12
September
5.5
7
8
4
5
October
0.1
0
1
4
-1
November
-7.2
-4
-8
-5
-8
December
-13.9
-10
-10
-12
-13
Average
-7.8
-17.2
-5.2
-5.4
-3.0
-4.1
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.