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
87.4
85
86
78
89
91
February
83.7
64
80
87
89
85
March
90.0
96
83
86
91
90
April
92.2
91
87
89
88
May
96.2
97
93
97
100
June
92.4
93
95
91
91
July
84.5
82
77
86
90
August
86.8
79
84
93
79
September
82.0
90
77
76
86
October
87.1
96
78
91
83
November
81.7
86
89
80
91
December
89.3
93
95
83
82
Average
87.6
81.6
88.0
84.9
88.3
88.0
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
4
1
3
-1
February
2.4
3
2
4
1
4
March
4.7
6
4
6
4
4
April
8.4
8
7
9
8
May
11.9
13
13
11
14
June
15.2
15
17
16
14
July
16.9
18
17
17
16
August
16.4
17
17
16
15
September
13.7
13
14
12
14
October
9.1
10
10
8
8
November
4.0
6
3
4
3
December
2.6
4
-1
-2
5
Average
8.3
3.3
9.5
9.4
8.3
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
-2.4
-2
1
-3
0
-4
February
-3.7
-2
-2
0
-3
0
March
-1.1
-1
-2
1
0
-2
April
1.9
2
1
2
2
May
5.6
6
5
6
6
June
9.2
9
9
10
9
July
11.3
12
11
11
11
August
11.2
12
12
11
11
September
8.5
9
9
9
8
October
4.8
5
6
4
4
November
0.6
2
0
1
0
December
-1.4
1
-4
-5
2
Average
3.4
-2.7
4.6
4.2
3.7
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
33.9
41
48
36
42
28
February
30.8
33
38
39
36
41
March
24.8
22
28
36
32
24
April
25.0
43
19
26
25
May
17.3
18
19
26
8
June
17.1
21
16
12
24
July
16.0
14
20
12
17
August
15.7
14
16
10
28
September
23.5
30
25
36
17
October
31.3
31
35
35
26
November
29.3
42
28
37
25
December
36.1
57
27
28
37
Average
24.4
31.2
29.8
25.0
25.9
24.0
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
4.2
5
3
4
5
5
February
3.6
3
4
3
6
3
March
3.9
3
5
3
4
4
April
3.5
4
4
3
3
May
2.3
2
3
2
3
June
2.0
2
2
2
2
July
1.7
2
2
2
2
August
1.7
1
1
2
2
September
1.8
3
1
2
2
October
2.7
3
2
3
3
November
3.3
3
4
4
4
December
4.2
4
4
4
5
Average
2.9
3.7
2.8
2.6
2.9
3.0
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
053°
082°
057°
082°
051°
February
053°
055°
082°
063°
101°
March
087°
061°
092°
066°
031°
April
077°
053°
050°
097°
May
117°
113°
101°
123°
June
101°
148°
133°
072°
July
330°
121°
209°
042°
August
270°
002°
094°
100°
September
100°
121°
096°
089°
October
084°
102°
100°
067°
November
078°
061°
077°
063°
December
088°
058°
056°
084°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.