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
87.2
80
90
83
95
February
91.4
90
88
90
94
March
94.6
91
93
91
0
April
96.9
96
97
96
May
96.8
100
93
98
June
99.2
99
99
100
July
99.1
98
99
100
100
August
97.0
99
94
100
96
September
97.4
97
98
97
99
October
94.5
97
95
98
89
November
96.3
96
99
97
93
December
87.8
76
92
85
93
Average
94.0
84.9
94.3
94.8
96.1
94.5
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
-3.6
-4
-2
-8
-1
February
0.9
-1
-4
-3
1
March
7.1
2
2
5
2
April
13.7
10
12
13
May
19.9
19
18
18
June
26.5
22
25
27
July
29.5
29
28
29
27
August
27.6
27
27
22
30
September
24.5
24
25
24
24
October
15.0
16
14
14
16
November
7.5
8
4
10
6
December
-1.9
-2
-4
2
-1
Average
10.0
-3.3
12.3
12.3
13.4
15.7
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.