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
69
86
98
96
85
February
82.1
85
74
75
77
92
March
92.2
94
94
87
86
April
94.3
92
99
94
85
May
98.4
99
97
100
100
June
95.7
98
81
100
97
July
90.4
99
70
94
97
August
88.2
77
93
89
86
September
90.5
86
84
94
92
October
84.9
85
83
76
82
November
82.3
85
76
84
89
December
85.7
89
71
69
97
Average
89.0
77.4
89.8
85.8
90.6
91.3
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
-18.5
-20
-14
-16
-14
-26
February
-12.1
-11
-12
-12
-16
-14
March
-4.2
-3
-2
-7
-6
April
5.8
1
6
5
5
May
17.1
17
15
17
19
June
22.4
22
24
23
21
July
23.9
25
24
25
21
August
19.6
21
21
19
21
September
13.8
12
14
13
14
October
3.4
1
2
3
3
November
-9.0
-5
-9
-13
-12
December
-14.7
-16
-13
-13
-13
Average
1.9
-16.7
4.2
5.1
3.6
2.7
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.