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
69.4
73
66
57
75
63
February
74.6
79
63
62
76
71
March
82.7
79
89
78
77
89
April
91.7
84
92
85
95
May
95.0
98
95
91
95
June
96.3
99
97
91
96
July
95.6
95
98
91
95
August
94.5
99
95
93
88
September
86.5
85
81
84
80
October
78.0
75
71
86
82
November
65.0
61
72
61
53
December
68.4
48
70
84
70
Average
84.0
76.9
81.6
82.8
84.0
83.5
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
-1.9
-1
2
0
1
-3
February
0.5
2
1
3
-1
3
March
6.1
8
6
8
5
6
April
11.3
10
10
12
12
May
17.9
21
15
15
18
June
19.9
23
21
22
17
July
22.9
25
23
24
20
August
22.8
25
25
22
18
September
17.0
17
19
15
18
October
9.8
10
12
8
9
November
3.6
5
1
5
3
December
-1.1
2
-5
-7
3
Average
10.0
2.8
12.2
11.3
10.1
10.3
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
-4.5
-5
-1
-4
-2
-6
February
-5.4
-4
-3
-2
-5
-1
March
-2.5
-1
-3
1
-1
-2
April
1.5
2
0
2
2
May
6.7
8
5
6
7
June
9.7
10
10
11
9
July
12.5
13
13
13
12
August
12.7
13
14
13
12
September
9.3
9
10
9
10
October
3.9
5
7
3
4
November
0.1
2
-3
1
0
December
-4.0
-1
-9
-10
0
Average
2.8
-4.8
4.4
3.7
3.2
3.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
50.5
51
52
52
55
61
February
36.0
27
55
41
53
27
March
30.1
24
30
38
39
29
April
25.9
38
23
26
23
May
20.2
10
35
24
18
June
23.8
14
24
29
32
July
19.2
16
24
22
26
August
21.6
14
23
25
47
September
31.9
30
21
61
33
October
31.8
26
31
42
25
November
44.5
46
34
62
49
December
43.5
60
27
37
56
Average
30.6
33.4
31.1
30.3
37.5
34.1
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
9.7
11
8
8
10
10
February
10.0
11
8
8
12
8
March
8.9
8
10
7
10
11
April
8.4
8
8
9
9
May
7.2
7
7
7
8
June
7.0
7
7
6
7
July
6.8
6
6
6
8
August
7.8
7
7
8
9
September
7.2
6
7
8
7
October
7.3
7
8
10
7
November
8.0
7
8
9
8
December
8.6
6
9
12
8
Average
8.2
9.6
7.0
7.4
8.4
8.3
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
015°
044°
086°
043°
028°
February
004°
138°
162°
060°
182°
March
022°
019°
174°
171°
129°
April
170°
110°
176°
171°
May
209°
172°
178°
168°
June
183°
181°
187°
181°
July
183°
194°
193°
175°
August
182°
182°
182°
171°
September
175°
179°
173°
025°
October
048°
180°
120°
035°
November
150°
017°
171°
100°
December
115°
008°
013°
118°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.