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
68.1
60
68
71
69
69
February
76.4
74
72
72
84
79
March
81.3
78
85
73
80
79
April
82.4
69
86
78
87
May
89.3
91
83
88
86
June
87.1
83
88
89
83
July
92.9
92
86
92
95
August
89.6
91
88
94
87
September
83.3
82
80
82
93
October
76.2
67
78
73
84
November
67.8
77
64
69
63
December
68.1
68
73
72
57
Average
80.7
71.6
80.0
79.7
82.0
81.9
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
-10.8
-8
-7
-14
-7
-7
February
-8.6
-2
-7
-10
-9
-6
March
-1.4
2
-2
-2
2
1
April
6.7
6
6
10
5
May
16.7
20
19
17
15
June
22.5
24
22
24
22
July
25.2
24
23
24
27
August
23.0
22
23
26
23
September
17.6
21
18
17
16
October
9.4
10
12
14
5
November
-1.4
0
2
1
2
December
-7.3
-2
-6
-7
-6
Average
6.8
-3.3
9.2
8.3
9.3
8.0
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
-19.3
-15
-17
-27
-14
-16
February
-20.2
-14
-20
-25
-23
-18
March
-14.4
-10
-16
-13
-12
-13
April
-5.0
-4
-4
-2
-7
May
3.3
4
6
4
2
June
8.9
9
10
10
10
July
12.2
12
12
11
15
August
10.8
10
11
13
11
September
7.0
7
7
7
6
October
1.7
3
3
5
-2
November
-8.7
-7
-5
-5
-5
December
-15.0
-9
-16
-17
-14
Average
-5.8
-13.1
-3.7
-3.0
-2.1
-3.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
51.3
60
45
52
43
54
February
41.4
37
46
45
36
40
March
29.4
35
22
35
34
31
April
24.5
40
26
24
20
May
15.3
11
22
17
22
June
14.6
8
18
12
24
July
8.5
10
19
6
7
August
11.2
17
11
5
9
September
16.3
9
19
17
15
October
29.7
42
26
21
25
November
50.2
44
52
49
48
December
47.4
39
41
48
61
Average
27.6
42.7
25.5
28.1
23.4
26.9
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
7.9
8
7
10
7
8
February
8.6
8
9
8
7
11
March
9.2
9
8
9
11
9
April
9.2
10
10
8
9
May
8.5
8
8
9
9
June
7.8
7
9
8
8
July
7.5
6
8
7
7
August
7.5
7
7
9
7
September
8.0
7
7
8
9
October
8.6
9
9
6
9
November
8.7
9
9
9
9
December
8.2
8
7
9
8
Average
8.3
8.3
7.8
8.5
8.2
8.5
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
268°
259°
271°
275°
304°
February
278°
279°
279°
241°
271°
March
299°
326°
305°
282°
269°
April
335°
275°
004°
314°
May
324°
199°
275°
312°
June
358°
264°
257°
260°
July
261°
269°
288°
266°
August
294°
241°
227°
249°
September
251°
276°
258°
240°
October
309°
235°
238°
245°
November
256°
273°
249°
247°
December
241°
207°
261°
271°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.