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
77.8
84
66
71
96
76
February
76.4
76
83
65
75
79
March
75.4
59
75
70
80
85
April
77.2
83
76
80
91
May
79.4
87
76
89
73
June
72.9
52
73
73
79
July
66.3
44
71
65
67
August
73.1
68
62
68
77
September
74.0
65
75
80
66
October
80.7
77
77
87
79
November
79.4
85
74
83
74
December
78.5
73
70
84
73
Average
75.2
71.3
69.8
71.7
79.1
76.5
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
-1.5
-1
1
-2
-1
-1
February
-1.9
1
-1
0
-1
1
March
3.2
5
3
4
5
4
April
9.5
11
10
11
8
May
15.1
16
17
15
14
June
20.0
19
20
22
22
July
23.4
24
24
22
23
August
23.2
22
23
24
23
September
19.6
21
20
20
19
October
14.1
15
16
15
13
November
6.9
5
9
8
9
December
1.7
3
3
3
4
Average
10.2
1.5
11.6
12.3
11.8
11.6
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
-10.5
-9
-6
-14
-7
-9
February
-10.1
-8
-13
-10
-9
-9
March
-6.7
-2
-5
-4
-6
-4
April
0.0
1
1
1
-1
May
4.0
4
5
5
3
June
8.9
9
9
11
10
July
13.0
16
13
13
14
August
12.8
13
15
14
12
September
9.5
11
10
11
8
October
4.8
7
5
5
4
November
-2.5
-3
0
-2
1
December
-7.8
-4
-3
-7
-4
Average
0.8
-7.7
2.5
2.4
2.4
2.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
31.6
25
32
41
22
30
February
25.2
29
26
35
18
22
March
25.7
46
30
28
18
15
April
20.5
10
32
22
14
May
14.6
14
10
10
18
June
16.8
35
17
13
5
July
10.7
18
9
21
10
August
12.9
17
22
14
10
September
11.1
14
11
14
14
October
12.0
14
7
8
10
November
20.2
23
12
25
13
December
25.7
25
33
26
31
Average
19.8
34.4
21.2
20.0
16.8
15.0
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
10.7
11
11
12
10
10
February
10.7
12
10
12
10
10
March
11.5
11
11
11
12
12
April
10.7
10
11
12
11
May
9.9
11
9
10
11
June
8.9
9
8
9
9
July
7.9
7
9
8
7
August
7.6
8
7
7
9
September
8.8
8
9
9
10
October
9.1
8
7
8
10
November
10.6
10
12
9
10
December
10.0
11
11
10
10
Average
9.8
11.2
9.2
9.6
9.5
9.8
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
329°
357°
330°
346°
334°
February
299°
327°
260°
316°
264°
March
327°
355°
269°
266°
338°
April
258°
322°
351°
297°
May
264°
189°
247°
237°
June
094°
191°
213°
194°
July
192°
216°
227°
198°
August
201°
190°
198°
221°
September
282°
261°
233°
223°
October
233°
183°
355°
232°
November
286°
265°
299°
239°
December
290°
007°
307°
282°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.