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
72.1
68
71
72
83
76
February
73.7
61
68
82
84
77
March
82.9
86
80
76
88
85
April
85.5
85
76
95
84
May
90.7
92
85
98
91
June
88.1
79
90
88
91
July
92.4
92
86
93
94
August
89.2
89
90
90
88
September
90.2
95
86
97
93
October
87.3
80
90
82
96
November
82.4
80
83
83
89
December
74.1
65
81
79
85
Average
83.6
72.2
82.1
83.3
88.9
87.9
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
-4.4
-3
-2
-7
-2
-2
February
-3.2
1
-2
-5
-5
-2
March
1.4
5
1
0
4
3
April
7.5
9
6
10
7
May
16.5
18
18
17
16
June
22.0
23
22
23
23
July
24.5
23
24
24
26
August
23.6
23
24
26
23
September
19.9
21
20
20
17
October
12.2
13
13
16
9
November
4.5
6
7
5
8
December
-1.4
3
0
0
0
Average
9.3
0.9
11.4
10.5
11.6
10.6
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
-11.5
-8
-7
-16
-8
-7
February
-13.9
-7
-11
-17
-14
-12
March
-8.3
-4
-8
-8
-6
-6
April
-2.6
0
-1
1
-2
May
4.2
4
6
4
4
June
9.1
10
9
11
9
July
12.6
12
12
13
15
August
12.9
12
13
15
13
September
9.6
10
10
9
8
October
4.4
6
3
8
2
November
-3.6
-2
-1
-1
0
December
-7.3
-3
-6
-5
-6
Average
0.1
-7.7
1.9
0.5
2.1
1.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
46.8
47
47
63
33
54
February
41.6
40
44
46
33
39
March
28.0
34
27
41
24
25
April
23.4
28
28
17
26
May
12.2
15
13
7
7
June
11.2
15
12
10
8
July
6.9
10
7
7
6
August
8.3
8
14
5
8
September
11.5
7
14
12
16
October
22.2
27
22
20
14
November
36.8
36
37
29
24
December
39.1
27
35
47
34
Average
24.0
39.6
22.9
25.5
18.3
19.7
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
7.8
8
7
9
7
9
February
8.9
8
10
9
8
10
March
10.0
10
10
11
11
9
April
9.5
9
10
10
11
May
8.6
8
8
9
10
June
7.4
7
8
7
7
July
7.2
7
7
7
7
August
7.1
7
7
7
7
September
7.5
6
8
8
8
October
8.1
8
7
7
9
November
9.0
10
9
8
9
December
8.6
8
10
11
8
Average
8.4
9.0
8.1
8.5
8.1
8.7
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
291°
066°
334°
314°
333°
February
315°
306°
327°
271°
282°
March
304°
315°
309°
303°
322°
April
332°
318°
325°
298°
May
316°
309°
296°
316°
June
304°
298°
269°
281°
July
294°
288°
313°
291°
August
302°
283°
257°
305°
September
074°
321°
293°
282°
October
320°
305°
004°
295°
November
283°
280°
271°
281°
December
016°
338°
287°
299°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.