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
85.5
90
76
86
85
82
February
87.4
87
79
89
82
92
March
92.0
94
92
87
93
91
April
92.4
87
100
91
87
May
92.3
96
82
86
98
June
91.2
81
100
95
87
July
89.3
54
100
93
91
August
93.2
85
91
94
89
September
92.4
62
100
89
96
October
89.5
87
77
95
88
November
77.4
75
73
71
87
December
84.2
80
80
81
94
Average
89.6
90.5
79.2
89.8
89.1
90.2
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
-16.2
-19
-12
-19
-13
-19
February
-16.9
-10
-18
-19
-20
-14
March
-7.0
-6
-8
-9
-8
-10
April
2.6
7
1
1
-1
May
12.8
24
11
12
8
June
19.4
21
21
21
17
July
22.3
24
22
23
21
August
20.9
22
22
20
19
September
15.1
16
20
15
14
October
6.1
9
9
8
3
November
-8.9
-3
-7
-5
-9
December
-14.2
-5
-18
-22
-12
Average
1.4
-12.2
4.6
3.6
2.8
1.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.