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
80.0
67
71
82
90
84
February
82.0
79
78
77
81
76
March
89.2
97
87
86
79
92
April
93.2
89
91
89
88
May
96.9
94
100
96
100
June
96.4
94
98
90
95
July
93.4
96
80
97
95
August
92.5
92
94
89
88
September
93.4
95
92
95
92
October
90.4
92
81
95
96
November
86.7
88
83
85
83
December
86.3
89
82
84
76
Average
89.9
81.8
89.4
88.1
89.8
89.8
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
1.1
0
3
1
3
-1
February
1.4
2
1
4
-1
3
March
4.2
6
3
5
3
4
April
9.4
9
8
10
9
May
14.9
15
16
12
17
June
17.7
17
21
19
15
July
19.3
21
18
19
18
August
17.9
19
18
18
15
September
14.4
13
14
13
14
October
8.9
9
11
8
8
November
3.6
6
3
4
2
December
2.0
4
-1
-3
4
Average
8.8
2.8
10.0
10.0
8.8
9.0
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
-3.1
-4
0
-3
0
-5
February
-5.8
-4
-3
-1
-6
0
March
-3.7
-2
-4
0
-2
-3
April
1.2
2
0
1
1
May
5.8
6
4
6
6
June
9.2
9
9
10
9
July
11.4
11
12
12
11
August
11.0
11
12
11
11
September
7.7
9
9
9
7
October
4.1
4
6
3
3
November
-1.5
2
-1
-1
-2
December
-2.1
1
-6
-8
1
Average
2.5
-4.8
4.0
3.7
2.9
3.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
40.0
48
49
46
47
38
February
37.9
37
46
56
39
62
March
32.3
25
25
47
49
32
April
31.3
40
20
42
39
May
28.9
28
21
47
13
June
28.1
27
21
34
42
July
25.7
12
42
23
32
August
31.8
23
38
36
49
September
34.6
51
37
54
26
October
38.2
42
48
41
29
November
40.6
51
41
48
36
December
41.9
58
40
29
44
Average
33.6
35.8
35.4
36.6
40.2
35.8
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
7.1
6
7
8
8
8
February
6.8
5
6
8
9
9
March
8.1
9
9
9
8
8
April
8.0
8
9
7
8
May
7.6
8
8
7
7
June
6.5
7
7
7
6
July
6.1
6
7
6
7
August
6.7
7
7
7
7
September
7.1
8
8
8
7
October
7.8
8
8
9
7
November
6.8
8
8
6
7
December
7.8
10
7
4
10
Average
7.1
6.9
7.3
7.7
7.2
7.4
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
104°
111°
099°
107°
108°
February
108°
100°
108°
108°
108°
March
124°
107°
114°
109°
109°
April
131°
119°
128°
123°
May
145°
155°
117°
174°
June
146°
165°
155°
133°
July
229°
108°
150°
109°
August
120°
111°
107°
099°
September
105°
105°
108°
109°
October
109°
112°
116°
105°
November
102°
104°
105°
106°
December
107°
107°
103°
106°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.