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
79.2
66
80
83
69
February
80.1
76
77
83
72
March
82.5
81
91
65
86
April
89.6
67
91
91
May
80.6
0
97
99
June
73.7
1
87
93
July
90.4
92
98
95
August
87.4
82
84
85
September
89.4
86
84
87
95
October
86.3
78
71
94
93
November
80.0
72
78
84
80
December
75.0
55
87
74
Average
82.3
74.8
63.0
78.2
87.3
87.4
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
-1.2
-2
3
1
-5
February
0.0
2
1
-3
1
March
3.3
6
2
2
3
April
9.7
9
9
9
May
15.4
16
13
18
June
17.6
18
18
17
July
19.4
21
19
19
August
18.0
19
18
17
September
14.7
14
14
14
15
October
8.8
9
11
7
8
November
2.3
6
1
4
0
December
1.0
3
-2
2
Average
7.9
1.8
10.0
5.6
9.6
8.7
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
-6.7
-7
-1
-3
-9
February
-7.9
-4
-4
-9
-4
March
-4.8
-1
-4
-3
-4
April
1.9
2
1
2
May
7.1
7
7
8
June
10.2
10
10
11
July
12.5
13
12
13
August
11.6
12
12
12
September
8.6
10
10
9
9
October
4.0
5
6
3
3
November
-2.2
1
-3
-1
-5
December
-3.1
-1
-7
-2
Average
2.1
-5.8
4.1
1.4
3.6
2.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
34.6
47
41
38
36
February
26.6
32
36
24
43
March
20.5
22
19
23
15
April
14.8
22
12
15
May
11.9
11
13
5
June
10.2
8
11
16
July
9.1
9
5
14
August
17.8
17
26
26
September
24.5
41
41
36
16
October
33.4
57
34
34
23
November
31.7
52
33
32
28
December
42.9
69
28
43
Average
23.6
32.4
28.8
33.9
21.0
21.2
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
10.5
12
10
10
11
February
10.1
10
9
11
10
March
9.8
9
9
10
11
April
9.2
9
11
9
May
8.6
8
8
8
June
6.7
7
6
7
July
6.3
5
6
7
August
6.9
6
8
7
September
7.7
8
8
8
8
October
8.8
7
9
10
8
November
9.4
9
9
11
10
December
10.1
12
10
10
Average
8.7
10.0
7.9
9.1
8.6
8.6
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
303°
341°
321°
306°
February
295°
320°
301°
355°
March
305°
303°
301°
295°
April
329°
299°
091°
May
106°
103°
134°
June
112°
114°
113°
July
124°
115°
103°
August
106°
097°
094°
September
083°
091°
074°
033°
October
028°
078°
037°
347°
November
336°
324°
309°
308°
December
358°
002°
323°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.