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
85.2
81
85
February
81.3
67
71
100
March
90.6
90
90
88
88
April
94.5
96
100
85
73
May
90.4
95
90
89
100
June
74.9
72
75
74
71
July
68.0
65
67
73
71
August
73.0
78
64
81
82
September
95.6
99
93
94
90
October
94.8
91
99
100
100
November
93.5
91
96
100
December
88.4
100
75
100
Average
86.0
84.1
86.0
84.2
84.3
85.5
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
2.6
3
3
February
1.0
-1
-1
2
March
3.9
3
5
2
2
April
6.2
7
7
7
4
May
9.6
11
11
8
9
June
11.9
12
15
11
10
July
13.6
15
14
13
13
August
14.5
16
15
14
13
September
12.5
13
13
11
11
October
8.5
9
10
6
7
November
4.5
6
4
2
December
3.3
3
3
4
Average
8.1
2.2
10.5
10.7
7.8
7.4
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
1.8
1
2
February
0.4
-3
-2
2
March
2.0
-1
2
1
2
April
3.7
3
2
4
3
May
6.8
6
5
7
8
June
10.1
9
10
10
10
July
11.8
11
12
12
12
August
12.4
12
12
13
12
September
10.3
10
10
10
9
October
6.9
7
8
6
7
November
3.2
3
2
1
December
2.4
2
1
3
Average
6.2
-1.0
7.2
7.3
6.6
6.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
53.6
60
50
February
32.0
33
36
46
March
33.7
47
29
20
25
April
28.1
30
17
35
33
May
27.7
32
15
43
15
June
25.5
29
20
34
33
July
28.5
19
41
13
38
August
27.5
23
32
28
24
September
35.4
42
35
42
31
October
39.8
42
33
32
20
November
44.5
56
37
25
December
55.1
0
63
56
Average
34.3
43.5
32.8
30.5
33.6
31.9
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
6.8
7
7
February
10.6
15
10
8
March
6.7
7
5
7
5
April
5.8
5
7
6
4
May
4.7
5
4
5
4
June
3.9
5
3
2
4
July
2.7
2
3
2
4
August
3.5
3
3
5
5
September
4.2
5
4
4
4
October
5.9
6
6
6
4
November
6.7
6
7
4
December
7.8
11
8
6
Average
5.7
9.0
4.6
4.6
5.0
4.5
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
076°
195°
February
049°
349°
079°
March
077°
090°
297°
350°
April
104°
030°
064°
092°
May
092°
038°
069°
081°
June
067°
079°
301°
342°
July
125°
107°
074°
090°
August
054°
003°
274°
150°
September
095°
114°
097°
097°
October
089°
165°
105°
083°
November
094°
081°
281°
December
090°
360°
090°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.