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
78.0
74
68
78
91
73
February
79.9
83
63
86
82
72
March
90.8
88
83
98
86
93
April
92.6
89
94
88
May
97.8
96
100
99
June
97.7
96
97
95
July
95.7
96
99
92
August
89.8
89
88
92
September
91.9
91
92
98
October
87.9
87
81
92
November
78.4
71
83
79
December
79.5
82
81
85
Average
87.3
82.7
70.5
90.1
91.4
90.4
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
-17.0
-18
-14
-18
-13
-25
February
-13.4
-9
-13
-15
-18
-18
March
-5.4
-6
-8
-4
-7
-6
April
2.2
0
2
3
May
12.7
5
15
17
June
20.3
21
19
20
July
20.7
20
19
18
August
16.6
16
16
20
September
11.4
12
10
11
October
2.5
2
1
3
November
-10.8
-8
-15
-9
December
-14.8
-14
-13
-13
Average
-1.6
-11.0
-12.1
1.8
1.3
1.6
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.