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
79.5
85
66
83
87
75
February
84.5
86
76
84
96
85
March
92.5
92
90
95
96
90
April
90.4
84
87
94
91
May
78.6
81
63
80
75
June
0
0
0
0
July
84.2
55
82
90
94
August
78.9
62
74
86
82
September
73.6
72
66
77
64
October
70.0
57
79
62
77
November
81.3
78
78
75
92
December
88.6
73
100
100
100
Average
82.5
88.7
72.5
78.1
84.2
82.1
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
-21.2
-26
-19
-23
-20
-24
February
-20.1
-17
-25
-24
-26
-23
March
-13.0
-16
-13
-16
-17
-13
April
-6.8
-9
-5
-4
-3
May
8.5
11
8
7
7
June
17.8
20
16
20
19
July
21.5
27
22
22
16
August
16.2
18
18
16
17
September
9.6
12
10
10
9
October
-2.9
-1
-2
-1
-2
November
-12.3
-9
-9
-14
-12
December
-19.5
-16
-18
-21
-21
Average
-4.5
-20.3
-1.9
-2.7
-3.9
-3.3
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.