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
96
77
83
74
February
93.4
97
92
95
95
March
92.8
96
85
97
96
April
99.2
100
99
99
99
May
99.5
100
100
June
99.7
100
100
July
99.7
99
100
August
99.4
100
100
September
98.9
100
100
100
October
96.9
97
99
99
November
94.8
94
99
98
December
89.4
96
82
86
Average
95.6
96.9
93.9
95.6
95.9
95.8
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
-1.1
4
-4
-2
-3
February
3.2
7
-5
5
3
March
10.2
11
3
12
13
April
17.7
19
15
18
18
May
23.1
24
24
June
30.7
33
29
July
34.2
35
35
August
32.4
31
35
September
26.6
26
25
27
October
16.8
18
18
20
November
8.2
8
6
9
December
1.0
3
-4
-1
Average
14.4
9.8
12.7
8.7
14.6
17.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.