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
72.2
63
62
67
85
February
60.9
61
50
39
64
March
66.9
39
61
53
73
April
60.9
43
61
54
61
May
53.9
45
49
41
48
60
June
42.2
30
30
49
30
52
July
25.7
13
14
34
30
33
August
46.8
39
36
64
71
September
71.3
78
62
78
October
81.1
85
76
83
November
76.0
64
64
91
December
70.9
51
67
57
Average
55.9
36.5
49.0
50.6
57.0
57.9
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
-1.4
0
-1
-3
-2
February
0.5
0
0
-1
0
March
0.5
-2
1
-1
1
April
2.6
2
2
1
4
May
5.5
4
4
5
6
7
June
9.2
8
8
9
9
10
July
11.0
10
11
11
11
13
August
11.6
12
11
12
13
September
10.6
10
10
10
October
6.6
7
6
6
November
3.9
5
4
0
December
1.3
0
4
3
Average
5.3
3.1
4.9
4.6
7.1
5.1
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
-5.6
-4
-4
-7
-5
February
-4.6
-4
-4
-5
-4
March
-4.3
-5
-3
-6
-3
April
-2.4
-2
-3
-3
0
May
1.1
0
0
0
2
3
June
4.4
3
3
4
5
5
July
7.2
6
8
6
7
9
August
8.0
9
7
9
11
September
6.4
6
6
6
October
2.9
4
2
2
November
0.4
1
1
-3
December
-3.5
-4
0
-1
Average
1.3
-1.2
0.9
0.4
3.4
1.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
29.7
27
39
27
17
February
32.0
32
41
27
25
March
28.2
47
34
8
16
April
25.5
30
42
22
0
May
16.5
25
20
3
7
0
June
13.2
21
13
14
12
0
July
16.2
14
13
15
16
7
August
16.5
15
12
16
17
September
20.0
15
26
16
October
27.0
14
26
27
November
30.5
30
28
23
December
31.0
47
17
16
Average
20.8
25.6
23.8
17.4
16.5
7.2
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
16.5
18
16
18
17
February
16.7
16
17
14
16
March
15.6
16
16
16
13
April
13.5
14
13
13
14
May
12.9
14
14
11
13
11
June
10.7
13
9
11
11
10
July
10.3
11
10
11
9
9
August
11.7
12
13
11
7
September
13.2
13
15
12
October
15.6
14
16
18
November
15.9
18
17
14
December
16.3
18
19
17
Average
13.2
13.7
13.4
13.9
12.4
12.1
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
044°
067°
052°
076°
February
007°
079°
076°
071°
March
025°
291°
019°
152°
April
286°
053°
084°
118°
May
352°
336°
348°
059°
085°
June
062°
047°
089°
003°
002°
July
238°
223°
258°
208°
188°
August
199°
274°
211°
071°
September
245°
269°
291°
October
085°
295°
286°
November
287°
067°
016°
December
027°
165°
231°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.