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
71.1
77
53
67
80
68
February
73.1
64
71
66
80
76
March
73.6
52
74
71
83
77
April
72.9
75
79
70
70
81
May
76.0
74
77
76
88
76
June
69.1
61
44
71
81
74
July
70.4
61
50
75
68
73
August
76.8
72
67
71
74
82
September
78.2
83
69
75
76
74
October
80.6
87
77
69
85
78
November
74.2
61
83
80
73
74
December
72.8
66
55
82
72
Average
74.3
69.1
66.2
71.2
78.2
75.6
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
0.5
-1
3
0
0
0
February
0.8
1
0
1
0
2
March
3.7
5
3
5
6
3
April
9.5
9
11
10
11
8
May
15.4
17
15
17
15
15
June
20.8
21
20
20
24
22
July
24.6
26
26
25
23
24
August
24.3
24
22
25
25
25
September
20.3
21
21
20
20
20
October
14.6
15
16
16
15
14
November
8.1
9
6
10
9
10
December
2.7
4
4
3
6
Average
12.3
13.3
12.2
13.1
12.6
12.3
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
-7.2
-7
-4
-10
-5
-7
February
-8.7
-6
-10
-8
-6
-7
March
-4.2
-1
-4
-4
-5
-3
April
1.0
1
1
2
2
0
May
5.1
7
4
6
5
5
June
11.1
12
11
11
13
12
July
15.7
16
18
15
15
16
August
15.6
15
15
17
16
15
September
11.9
12
13
12
13
11
October
6.8
6
8
8
8
6
November
0.7
3
-1
2
1
2
December
-4.0
-2
-2
-5
-2
Average
4.0
5.2
4.3
4.4
4.4
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
35.1
37
43
39
28
38
February
29.3
34
29
39
23
27
March
27.4
37
34
28
21
21
April
22.3
20
12
31
22
25
May
16.6
14
17
13
18
19
June
16.2
20
28
19
7
10
July
11.7
14
21
10
18
7
August
11.7
12
23
13
11
7
September
14.3
17
20
18
18
11
October
12.5
10
18
11
11
11
November
23.8
35
20
20
30
13
December
30.5
35
48
23
35
Average
19.5
21.4
24.3
21.9
18.0
17.4
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
11.9
12
11
12
11
11
February
12.3
12
12
13
13
11
March
13.0
13
13
12
13
13
April
12.0
11
11
12
13
12
May
10.7
9
12
10
10
12
June
9.6
10
9
8
10
9
July
8.3
9
8
10
8
8
August
8.4
8
9
8
8
10
September
9.4
9
9
9
10
10
October
9.8
10
9
8
9
10
November
11.9
13
11
13
11
10
December
11.7
12
13
12
12
Average
10.5
10.3
10.3
10.5
10.5
10.5
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
309°
309°
304°
337°
319°
February
305°
316°
266°
297°
263°
March
230°
344°
253°
265°
320°
April
350°
305°
286°
339°
297°
May
128°
300°
276°
278°
263°
June
221°
143°
202°
222°
187°
July
208°
189°
227°
227°
205°
August
216°
207°
188°
212°
250°
September
082°
207°
279°
225°
232°
October
264°
264°
190°
320°
246°
November
314°
282°
266°
273°
246°
December
283°
006°
294°
261°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.