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
77.9
73
79
80
78
76
February
81.6
80
79
94
74
84
March
85.4
74
75
86
96
90
April
90.3
98
88
74
97
94
May
96.1
94
93
97
97
June
98.8
96
98
100
100
July
98.9
98
100
100
99
August
97.2
93
97
95
100
September
97.2
97
95
100
99
October
96.4
98
93
99
96
November
87.4
96
68
90
89
December
82.9
80
76
72
86
Average
90.7
81.3
89.5
88.1
92.3
93.0
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
-4.3
-1
-4
-4
-2
-2
February
-2.3
1
-2
-2
-2
-2
March
2.8
3
0
5
4
3
April
7.9
10
7
8
10
8
May
15.1
18
14
16
17
June
20.6
19
22
26
20
July
26.7
27
29
29
26
August
25.8
24
27
25
28
September
21.4
21
24
22
22
October
11.7
13
14
12
13
November
3.6
6
-2
6
3
December
-2.6
0
-4
0
-2
Average
9.8
3.0
10.8
11.4
12.3
11.2
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.