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
79.6
68
85
73
100
83
February
82.7
72
80
75
86
82
March
88.8
88
94
81
90
94
April
93.9
94
93
90
92
85
May
97.0
97
96
100
June
95.3
96
95
94
July
88.7
96
67
97
August
92.9
96
95
89
September
89.6
88
77
94
97
October
88.1
92
78
95
61
November
81.9
74
82
79
100
December
84.3
85
81
83
33
Average
88.1
81.8
90.5
78.7
88.6
91.2
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
1
4
1
4
-1
February
2.1
3
2
3
1
3
March
4.6
6
4
6
3
4
April
9.2
11
9
7
9
7
May
13.9
15
11
15
June
16.5
17
18
15
July
19.3
21
19
18
August
18.1
19
18
16
September
14.7
14
13
13
15
October
9.2
10
11
8
8
November
3.8
5
3
3
-1
December
1.8
3
-1
-2
8
Average
8.6
5.2
10.2
5.0
9.3
9.7
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
-3.5
-3
0
-1
4
-5
February
-5.8
-3
-4
-2
-4
-1
March
-4.9
-3
-5
-1
-2
-4
April
-1.9
-1
0
1
-1
0
May
4.3
4
4
4
June
8.2
8
9
8
July
10.5
10
10
11
August
10.3
11
11
11
September
6.0
8
2
8
6
October
2.7
4
1
2
4
November
-1.4
1
-2
-1
-2
December
-3.4
0
-6
-8
6
Average
1.5
-3.6
2.9
-2.8
2.7
3.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
36.2
44
46
36
100
32
February
26.0
31
37
50
31
1
March
27.5
28
31
47
31
7
April
26.1
16
41
42
25
31
May
21.0
20
31
9
June
20.1
21
20
26
July
14.2
11
7
16
August
19.8
18
18
36
September
25.6
39
29
38
20
October
35.6
41
31
41
50
November
36.4
41
39
39
11
December
37.6
60
34
27
100
Average
26.7
28.7
31.8
38.4
26.4
19.9
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
5.6
6
5
5
7
7
February
4.9
4
4
6
9
5
March
5.5
6
6
5
4
5
April
5.0
4
5
6
5
4
May
4.1
4
4
4
June
3.7
4
3
4
July
3.0
3
3
4
August
3.5
4
3
4
September
3.5
4
3
4
4
October
4.2
5
4
4
6
November
4.3
3
4
4
6
December
4.2
4
4
4
4
Average
4.4
4.9
4.2
4.5
4.1
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
092°
084°
088°
080°
084°
February
089°
089°
087°
086°
081°
March
089°
085°
086°
091°
090°
April
088°
088°
084°
087°
097°
May
086°
087°
088°
June
090°
095°
098°
July
125°
088°
083°
August
084°
087°
084°
September
085°
090°
087°
086°
October
085°
090°
086°
084°
November
088°
080°
084°
083°
December
087°
087°
090°
078°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.