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
70.6
72
70
65
51
80
February
69.9
49
64
81
70
76
March
66.9
47
74
78
63
April
62.1
57
46
50
75
May
70.9
66
76
79
80
June
62.3
35
66
75
65
July
69.5
63
83
66
59
August
74.7
67
64
80
81
September
73.3
63
61
77
84
October
72.8
58
72
68
74
November
72.2
75
70
72
76
December
66.7
70
26
72
64
Average
68.4
59.8
59.7
67.0
70.4
72.6
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
0.3
-1
2
2
0
-2
February
-1.4
0
-3
2
0
-1
March
1.2
-1
2
3
0
April
5.3
4
5
6
4
May
9.8
10
11
11
11
June
15.8
14
17
18
18
July
20.8
24
23
20
18
August
21.0
19
22
21
22
September
17.2
18
18
19
19
October
11.6
12
15
10
12
November
6.5
5
7
8
7
December
2.3
3
3
2
5
Average
8.1
-1.2
8.9
10.8
9.9
9.5
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
-6.4
-7
-4
-6
-3
-7
February
-7.0
-4
-10
-6
-5
-8
March
-5.4
-4
-5
-4
-6
April
-2.9
-2
-1
1
-2
May
1.5
2
2
3
2
June
7.1
6
9
8
10
July
12.4
16
14
11
11
August
13.4
13
15
13
13
September
10.0
11
12
10
11
October
5.4
6
7
6
6
November
0.4
-1
0
2
0
December
-3.3
-2
0
-4
0
Average
1.5
-6.6
2.7
3.6
3.2
2.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
38.5
47
37
44
43
33
February
41.4
44
53
41
40
39
March
32.2
46
36
25
36
April
28.0
33
32
36
18
May
18.9
27
18
10
13
June
20.3
30
22
14
20
July
14.9
15
8
20
21
August
14.3
26
16
6
11
September
19.5
21
31
11
12
October
20.9
33
9
30
23
November
28.1
33
32
25
21
December
38.0
34
52
39
34
Average
26.9
45.3
31.0
26.0
22.7
21.9
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
15.3
16
15
17
14
13
February
17.3
17
17
17
18
19
March
16.3
16
17
17
17
April
15.0
15
14
14
15
May
14.0
15
11
15
16
June
12.2
10
12
13
12
July
11.8
11
13
12
11
August
11.5
10
11
13
12
September
12.6
11
14
12
14
October
12.7
12
12
14
13
November
15.3
12
16
14
15
December
15.3
15
14
17
14
Average
14.2
16.4
13.1
13.8
14.2
14.0
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
288°
264°
235°
340°
303°
February
311°
310°
271°
295°
279°
March
353°
262°
270°
297°
April
336°
291°
114°
271°
May
270°
282°
275°
263°
June
355°
261°
261°
244°
July
242°
250°
251°
256°
August
221°
261°
277°
260°
September
268°
278°
253°
253°
October
268°
270°
338°
255°
November
291°
280°
230°
269°
December
274°
082°
279°
255°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.