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
75.9
85
58
73
81
74
February
75.6
66
72
70
83
81
March
74.8
67
68
70
90
75
April
70.2
82
60
56
75
May
75.7
74
76
77
83
June
70.3
46
70
76
71
July
75.4
54
89
68
70
August
84.7
81
70
84
88
September
79.2
61
77
76
85
October
85.3
80
75
96
85
November
83.3
91
83
80
87
December
80.4
69
51
88
83
Average
76.8
71.8
68.4
72.7
78.6
79.2
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
0.7
0
4
1
1
0
February
0.1
1
-1
1
1
0
March
2.2
4
1
3
4
1
April
7.1
8
7
8
6
May
12.4
13
14
13
13
June
18.8
18
19
22
20
July
23.4
25
25
21
22
August
23.7
22
24
25
24
September
19.6
21
19
20
20
October
14.1
16
16
15
14
November
8.1
7
9
10
10
December
3.0
5
4
3
6
Average
10.0
1.6
11.3
12.2
11.7
11.2
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
-6.0
-6
-3
-7
-4
-7
February
-8.4
-5
-9
-7
-5
-8
March
-5.4
-2
-4
-5
-5
-5
April
-1.5
-1
0
1
-1
May
2.7
2
3
4
3
June
9.0
9
10
11
10
July
14.1
17
14
13
14
August
14.5
14
16
15
14
September
10.9
13
12
12
11
October
5.7
7
7
7
5
November
0.6
0
2
2
1
December
-3.0
-2
-1
-3
-1
Average
2.1
-5.5
3.7
3.8
3.9
2.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
41.2
32
47
57
36
53
February
32.4
36
35
38
37
27
March
26.7
32
28
31
20
30
April
21.3
8
24
33
24
May
19.5
21
15
15
22
June
16.7
22
18
9
15
July
12.5
21
11
18
16
August
11.4
18
19
5
9
September
16.3
23
21
13
12
October
17.0
26
15
13
19
November
25.9
20
27
26
21
December
35.8
40
48
33
37
Average
23.0
33.2
24.6
24.3
19.9
22.3
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
12.6
12
12
13
12
12
February
13.2
13
13
14
14
12
March
13.1
12
13
13
13
14
April
12.6
12
13
13
13
May
11.8
13
10
12
13
June
10.0
10
10
10
10
July
9.2
8
11
10
8
August
9.4
10
9
9
10
September
10.5
10
11
11
11
October
10.4
10
9
11
11
November
12.8
11
14
12
12
December
12.9
13
14
13
12
Average
11.5
12.3
10.9
11.3
11.4
11.2
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
286°
278°
275°
328°
320°
February
292°
299°
263°
287°
264°
March
210°
357°
255°
256°
320°
April
317°
320°
040°
329°
May
286°
323°
268°
268°
June
135°
203°
223°
229°
July
191°
240°
229°
193°
August
192°
208°
239°
253°
September
197°
271°
237°
233°
October
245°
219°
325°
249°
November
276°
261°
231°
244°
December
279°
064°
280°
216°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.