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
79.2
78
69
82
81
85
February
81.5
92
74
69
81
86
March
84.2
73
81
78
94
95
April
92.7
93
93
93
95
May
97.4
98
95
98
98
June
94.1
82
95
100
97
July
95.1
87
97
97
93
August
93.6
93
82
95
97
September
91.1
89
81
93
96
October
91.7
87
86
93
93
November
87.2
88
78
96
93
December
85.4
70
88
86
91
Average
89.6
80.2
84.7
85.5
92.9
93.8
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
-4.4
-3
-1
-6
-4
-2
February
-1.0
2
-1
-2
-3
-1
March
3.0
5
3
3
6
5
April
10.3
13
10
13
9
May
18.7
19
22
18
18
June
22.8
22
23
25
24
July
25.6
26
26
23
27
August
24.1
22
25
27
24
September
20.1
21
18
21
20
October
14.4
15
16
15
13
November
4.7
4
7
5
9
December
-1.5
2
2
1
1
Average
10.3
1.4
12.1
12.3
12.2
12.1
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
-13.9
-10
-8
-20
-11
-10
February
-12.2
-9
-12
-13
-14
-12
March
-7.3
-4
-6
-6
-6
-5
April
0.1
1
0
1
-1
May
5.7
4
7
6
5
June
11.1
12
11
13
11
July
14.3
16
13
13
15
August
13.3
13
15
15
13
September
9.1
11
9
8
7
October
4.1
6
1
6
3
November
-4.4
-3
-1
-3
-1
December
-9.5
-5
-5
-8
-6
Average
0.2
-8.6
2.5
1.2
1.7
1.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
45.3
55
63
42
41
32
February
36.2
27
46
52
37
32
March
31.9
40
46
48
20
19
April
22.4
27
29
22
19
May
12.7
14
21
10
11
June
12.6
25
18
7
10
July
9.4
23
8
7
7
August
10.4
19
20
6
11
September
11.5
17
23
10
4
October
16.9
29
17
14
19
November
29.6
36
41
19
22
December
33.8
42
39
34
29
Average
22.3
41.1
31.7
28.8
17.3
16.1
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
6.7
7
6
7
6
6
February
8.0
8
8
9
7
7
March
8.5
8
8
9
9
8
April
8.3
9
9
8
9
May
7.4
8
6
7
8
June
6.3
5
7
7
6
July
5.7
5
7
6
6
August
5.5
6
5
5
6
September
5.3
4
5
6
6
October
6.3
6
6
5
7
November
6.9
7
7
7
7
December
6.5
5
8
7
7
Average
6.9
7.7
6.4
7.1
6.6
7.0
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
255°
277°
279°
280°
272°
February
259°
271°
263°
269°
259°
March
276°
279°
264°
263°
258°
April
223°
276°
311°
271°
May
285°
258°
278°
278°
June
048°
258°
251°
257°
July
233°
248°
275°
250°
August
252°
272°
236°
263°
September
284°
295°
249°
246°
October
236°
229°
290°
244°
November
259°
256°
257°
247°
December
277°
275°
269°
247°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.