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
84.3
81
87
88
85
94
February
86.9
82
87
92
88
92
March
82.5
76
75
84
80
88
April
86.6
88
83
82
92
May
91.9
96
92
87
94
June
89.9
81
91
94
86
July
94.5
89
90
99
97
August
94.2
91
95
96
97
September
92.1
83
89
90
97
October
87.0
91
95
80
84
November
75.0
80
75
73
80
December
80.4
88
60
76
85
Average
87.2
79.1
86.6
87.6
86.9
91.0
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
-15.5
-12
-14
-19
-10
-15
February
-13.3
-8
-16
-15
-10
-12
March
-6.5
-2
-4
-7
-5
-7
April
1.3
4
2
5
0
May
9.3
11
10
9
8
June
16.3
19
17
17
16
July
20.1
23
18
20
21
August
18.9
17
20
21
18
September
13.0
16
14
14
12
October
5.8
8
9
9
2
November
-5.8
-4
-4
-1
-3
December
-10.5
-7
-6
-10
-8
Average
1.9
-8.5
4.6
3.6
5.0
2.8
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.