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
71.0
72
92
78
81
February
90.1
98
90
95
85
90
March
87.9
92
91
91
92
84
April
89.1
91
97
93
May
86.9
60
93
94
June
79.4
0
96
96
July
80.7
0
94
96
August
85.3
95
99
September
89.6
96
92
October
90.4
90
93
November
90.4
99
89
December
86.7
88
89
Average
84.8
94.4
85.0
58.6
92.3
91.6
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
-2.4
-3
-5
-2
0
February
1.8
10
3
0
-7
1
March
8.9
13
7
8
10
10
April
14.3
12
16
15
May
20.5
15
21
20
June
23.2
0
29
28
July
24.1
0
28
30
August
24.6
28
28
September
24.5
27
23
October
16.2
19
15
November
7.5
10
12
December
3.1
6
2
Average
11.6
11.4
1.8
4.5
15.5
15.0
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.