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
65.8
68
48
63
79
69
February
67.6
59
64
56
71
81
March
67.2
50
53
60
85
73
April
68.8
65
60
58
79
May
72.3
63
66
77
82
June
66.1
31
72
77
68
July
73.9
45
85
72
73
August
83.5
70
74
86
89
September
78.6
64
76
82
87
October
81.1
79
61
92
79
November
82.4
89
78
79
87
December
72.4
62
57
81
80
Average
73.3
58.2
58.6
67.9
78.0
78.9
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
0.4
-1
3
1
0
-1
February
-1.9
1
-1
1
0
0
March
2.3
4
1
3
5
1
April
7.6
8
8
9
6
May
12.5
13
14
13
14
June
19.0
18
19
22
20
July
23.3
25
25
21
23
August
23.4
22
24
25
24
September
19.6
21
19
20
20
October
14.0
15
16
14
14
November
7.9
6
10
10
10
December
2.8
5
4
3
5
Average
9.9
1.3
11.2
12.1
11.7
11.3
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
-7.5
-7
-3
-8
-5
-7
February
-9.9
-6
-10
-8
-6
-8
March
-5.2
-2
-4
-5
-5
-5
April
-1.6
-1
0
1
-1
May
2.9
2
4
3
3
June
9.7
10
10
12
11
July
14.2
17
15
13
14
August
14.5
14
16
15
14
September
10.7
12
11
12
10
October
5.6
7
7
6
5
November
0.5
0
2
2
1
December
-4.8
-1
-1
-4
-1
Average
2.0
-5.1
3.6
3.7
3.8
3.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
45.9
49
59
56
34
44
February
40.1
45
50
51
42
23
March
27.8
29
42
31
22
27
April
21.7
16
27
34
20
May
16.2
24
13
13
16
June
13.0
23
13
7
10
July
9.4
19
9
10
7
August
8.5
18
14
4
4
September
10.1
13
16
8
6
October
12.8
26
8
5
17
November
23.6
28
26
27
16
December
40.3
49
45
38
33
Average
21.9
40.2
29.6
23.9
18.4
16.8
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
10.1
10
10
10
9
9
February
11.1
11
11
12
12
10
March
10.6
10
10
11
10
11
April
10.2
10
10
10
10
May
9.4
10
8
9
10
June
8.3
9
8
8
7
July
7.2
7
8
8
6
August
7.4
8
7
7
8
September
7.9
8
8
8
8
October
8.4
8
7
8
9
November
10.4
9
12
10
9
December
10.4
10
10
11
10
Average
9.3
10.2
9.0
9.2
9.0
8.9
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
299°
307°
289°
310°
306°
February
294°
302°
267°
291°
270°
March
208°
319°
273°
272°
302°
April
300°
305°
014°
312°
May
309°
282°
281°
271°
June
092°
197°
224°
195°
July
150°
239°
250°
189°
August
184°
130°
233°
263°
September
213°
268°
239°
230°
October
271°
180°
308°
271°
November
288°
274°
252°
256°
December
291°
033°
282°
249°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.