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
75.2
76
63
70
72
76
February
81.7
79
86
78
77
86
March
79.3
62
76
78
93
79
April
77.8
84
71
61
89
May
83.6
80
91
84
90
June
82.0
49
84
93
89
July
89.9
85
94
83
86
August
90.3
78
82
95
97
September
88.7
75
86
92
96
October
85.9
74
85
89
94
November
83.8
86
85
82
90
December
81.9
80
71
87
73
Average
82.5
70.8
75.6
82.0
84.5
87.7
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
-2.3
-2
0
-4
-2
-1
February
-1.1
1
-2
0
-2
-1
March
2.7
5
2
4
5
2
April
9.0
10
10
9
8
May
16.2
16
18
16
17
June
21.7
20
21
24
24
July
25.8
27
26
23
26
August
25.1
23
25
26
26
September
20.6
21
20
20
21
October
14.6
16
17
15
14
November
6.4
5
8
7
9
December
0.9
3
3
2
4
Average
10.5
1.0
11.9
12.7
12.0
12.3
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
-10.2
-9
-6
-14
-7
-9
February
-10.1
-7
-13
-10
-9
-10
March
-6.7
-3
-5
-5
-6
-5
April
0.0
0
1
1
-1
May
4.5
4
6
4
5
June
10.6
11
11
13
11
July
14.9
18
15
14
15
August
14.5
14
16
15
14
September
10.3
12
10
12
10
October
5.3
7
6
7
4
November
-2.4
-3
0
-1
0
December
-7.7
-4
-3
-7
-4
Average
1.2
-7.8
3.1
3.0
3.0
2.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
37.5
30
44
43
39
42
February
29.8
28
29
33
30
28
March
28.5
43
32
29
20
29
April
23.3
11
34
35
12
May
18.0
23
12
16
14
June
16.6
35
18
6
8
July
10.6
13
10
18
15
August
10.7
21
19
5
5
September
12.4
18
10
15
15
October
13.8
25
9
9
9
November
23.5
22
15
30
16
December
26.2
27
40
18
34
Average
21.5
34.6
24.2
21.3
18.8
17.3
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
10.9
11
11
10
10
10
February
11.2
12
9
13
11
11
March
12.0
11
11
11
14
12
April
11.0
10
11
12
12
May
10.4
11
9
10
12
June
9.4
9
8
11
9
July
8.5
8
10
9
8
August
8.6
8
8
8
11
September
9.2
8
9
10
11
October
9.5
9
9
9
10
November
11.3
10
12
10
11
December
11.2
12
12
11
11
Average
10.3
11.3
9.6
10.0
10.2
10.6
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
265°
327°
272°
303°
290°
February
285°
299°
255°
269°
247°
March
293°
344°
253°
247°
302°
April
300°
319°
346°
286°
May
289°
214°
301°
248°
June
035°
177°
221°
195°
July
198°
227°
231°
196°
August
204°
212°
216°
238°
September
267°
257°
222°
225°
October
261°
211°
253°
227°
November
252°
255°
249°
237°
December
262°
353°
261°
243°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.