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
36.1
32
7
52
47
25
February
45.5
26
54
80
44
51
March
57.1
47
38
69
65
54
April
68.6
83
71
62
90
May
76.8
93
77
71
94
June
90.5
85
92
89
92
July
90.9
98
89
91
84
August
92.1
95
85
93
98
September
90.2
92
91
85
88
October
74.3
45
72
62
95
November
70.6
72
67
77
73
December
46.3
46
45
43
55
Average
67.2
35.2
69.2
76.9
68.3
82.2
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
-7.1
-8
-10
-5
-7
-8
February
-7.3
-7
-7
-6
-7
-8
March
-3.0
-4
-6
-3
-3
-3
April
0.4
0
-3
0
1
May
5.6
6
3
3
8
June
12.4
4
12
13
12
July
15.6
20
16
13
15
August
15.3
17
14
16
18
September
12.1
13
13
12
12
October
3.6
0
3
2
8
November
-2.3
-1
-4
0
0
December
-6.4
-5
-8
-4
-6
Average
2.3
-7.8
2.6
3.0
3.1
4.4
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-12.1
-13
-14
-11
-12
-11
February
-13.8
-12
-13
-13
-13
-12
March
-9.3
-10
-11
-10
-10
-7
April
-6.7
-7
-6
-6
-4
May
-1.9
1
-1
0
2
June
4.9
1
5
6
6
July
8.1
9
8
8
8
August
7.0
7
7
7
9
September
4.1
3
5
5
3
October
-4.8
-6
-3
-3
-1
November
-8.8
-7
-11
-5
-7
December
-11.3
-10
-12
-10
-12
Average
-4.1
-12.5
-5.9
-4.8
-3.3
-2.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
4.3
3
0
13
5
13
February
7.5
3
10
8
6
7
March
6.2
1
4
4
16
12
April
4.6
4
7
9
3
May
5.2
6
10
8
9
June
4.9
10
8
4
2
July
5.5
2
10
16
3
August
5.3
6
9
5
5
September
3.0
4
6
3
1
October
5.7
0
7
9
2
November
3.2
2
6
1
3
December
5.7
5
7
4
8
Average
4.7
2.4
3.8
8.1
7.0
4.2
Precipitation during daylight period
Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.
Wind speed (knots)
Month
Average
2024
2023
2022
2021
2020
January
16.8
14
17
16
20
11
February
20.7
19
24
21
19
18
March
18.3
16
18
18
15
19
April
21.2
24
20
19
21
May
12.5
13
17
14
17
June
8.2
13
15
12
19
July
9.8
17
12
11
13
August
10.5
14
10
14
13
September
12.0
16
13
14
12
October
17.1
15
13
14
26
November
19.4
20
19
20
17
December
15.8
18
20
13
15
Average
15.5
16.3
17.3
15.1
15.5
16.6
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2024
2023
2022
2021
2020
January
274°
261°
257°
252°
244°
February
277°
254°
251°
255°
262°
March
269°
245°
252°
244°
247°
April
258°
252°
255°
259°
May
236°
244°
247°
249°
June
257°
250°
254°
244°
July
264°
253°
245°
260°
August
259°
254°
259°
259°
September
259°
250°
252°
252°
October
262°
255°
249°
257°
November
275°
248°
257°
245°
December
277°
249°
249°
249°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.