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
73.7
83
51
82
60
95
February
66.1
62
80
76
73
March
61.8
38
57
74
69
65
April
78.3
79
76
78
55
May
64.8
55
45
72
79
June
0
0
0
0
July
57.2
51
96
30
64
August
75.8
73
74
79
65
September
83.0
80
74
91
94
October
83.4
65
83
89
88
November
75.5
82
56
66
93
December
62.8
60
13
75
100
Average
69.2
43.9
66.8
69.5
73.3
73.4
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
-14.3
-6
-14
-18
-14
-18
February
-15.3
-16
-16
-19
-23
March
-11.9
-6
-10
-10
-13
-13
April
-5.3
-11
-3
-6
-5
May
1.5
0
1
1
3
June
6.3
4
5
6
7
July
10.9
13
8
9
10
August
9.9
11
9
9
11
September
7.8
7
9
5
7
October
1.9
1
1
0
3
November
-5.9
-3
-3
-9
-2
December
-11.5
-10
-7
-16
-10
Average
-3.6
-6.0
-2.0
-3.3
-4.3
-3.3
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.