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
83.3
80
68
92
93
February
89.7
80
92
93
95
March
89.0
87
73
96
96
100
April
95.1
93
97
96
May
95.6
93
95
99
June
97.9
99
98
97
July
96.0
95
95
98
August
96.9
95
97
99
September
95.3
89
99
99
October
93.0
87
99
94
November
88.4
92
82
100
80
December
90.5
100
81
84
94
Average
92.4
82.5
90.1
90.7
95.6
95.5
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
-4.9
-5
-5
-4
2
February
-1.5
5
-2
-1
-4
March
4.9
4
-4
7
13
11
April
12.5
11
15
12
May
21.2
24
19
20
June
27.6
28
30
26
July
30.9
30
34
29
August
30.9
31
29
32
September
25.6
27
27
24
October
13.5
13
17
10
November
5.1
7
-2
9
6
December
-2.5
5
-11
-6
3
Average
10.1
1.2
13.9
-2.3
14.6
18.0
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.