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
75
79
75
90
98
February
81.8
77
87
74
96
81
March
78.6
79
68
84
80
71
April
92.0
95
91
94
80
May
89.9
89
85
97
97
June
0
0
0
0
July
85.4
84
90
77
85
August
85.8
83
85
81
88
September
88.6
87
98
83
90
October
87.3
80
79
96
89
November
79.3
74
67
88
86
December
84.4
73
55
93
100
Average
85.1
77.5
83.8
84.1
88.0
86.3
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
-16.5
-15
-12
-18
-13
-19
February
-14.3
-10
-16
-15
-18
-20
March
-8.2
-7
-8
-5
-10
-9
April
-2.5
-9
0
-3
-1
May
9.3
6
7
10
12
June
17.4
15
17
16
18
July
17.7
19
16
15
18
August
15.5
16
15
14
17
September
9.9
9
11
8
9
October
1.0
1
-1
0
2
November
-8.5
-5
-7
-15
-6
December
-13.9
-14
-10
-15
-12
Average
-2.5
-11.4
0.5
-1.8
-1.2
1.3
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.