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
81.1
67
81
72
91
82
February
80.3
91
82
87
82
93
March
83.7
91
91
86
82
73
April
82.9
85
84
82
78
May
65.9
54
51
57
69
June
0
0
0
0
July
81.7
68
85
76
77
August
73.5
75
73
80
74
September
72.8
83
69
68
72
October
71.8
61
88
73
67
November
78.9
82
76
76
81
December
0
0
0
0
Average
77.9
87.8
76.8
76.8
76.2
75.2
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
-22.7
-26
-20
-24
-22
-24
February
-23.0
-21
-28
-26
-28
-26
March
-18.6
-20
-17
-20
-21
-17
April
-11.2
-12
-11
-10
-9
May
1.8
5
3
0
1
June
11.5
14
11
13
12
July
16.7
22
17
18
12
August
12.8
15
15
13
14
September
7.3
9
7
8
7
October
-2.5
0
-2
0
-3
November
-12.8
-9
-10
-12
-12
December
-19.4
-15
-19
-22
-20
Average
-7.5
-23.6
-3.0
-5.7
-6.9
-6.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.