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
71.5
65
60
73
77
69
February
82.0
75
90
64
89
91
March
88.4
87
83
93
98
85
April
88.4
90
82
68
92
95
May
93.4
89
88
91
98
June
96.7
91
97
98
100
July
95.7
96
97
87
97
August
92.5
87
95
87
94
September
92.2
87
92
96
98
October
90.3
90
98
89
93
November
86.0
91
81
88
93
December
74.9
62
48
77
84
Average
87.9
80.3
84.9
85.0
89.7
92.3
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
-8.6
-7
-8
-11
-3
-7
February
-7.3
2
-6
-10
-10
-6
March
1.0
3
-5
0
9
1
April
9.2
14
5
5
13
8
May
20.8
25
19
20
18
June
27.3
29
27
29
28
July
28.4
27
29
30
29
August
26.9
27
28
28
27
September
22.1
25
23
25
21
October
12.0
13
15
16
9
November
2.0
5
1
4
7
December
-5.8
1
-6
-6
-1
Average
9.9
2.8
11.6
10.4
13.0
11.1
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
-17.6
-13
-16
-23
-12
-16
February
-18.9
-7
-18
-23
-19
-17
March
-9.0
-7
-15
-9
-5
-9
April
-2.2
0
-4
-3
-2
-3
May
6.4
9
8
4
5
June
13.7
16
13
13
14
July
15.3
13
16
16
17
August
13.9
14
15
15
14
September
9.6
11
9
11
8
October
1.7
3
2
5
-1
November
-7.2
-5
-7
-5
-6
December
-14.7
-6
-15
-16
-11
Average
-2.8
-7.3
0.3
-1.0
0.4
-1.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
22.8
31
22
34
14
27
February
18.4
14
9
44
14
11
March
11.1
18
18
6
3
9
April
14.2
12
23
34
12
10
May
6.7
5
10
4
9
June
3.9
4
2
5
4
July
2.7
1
3
2
3
August
4.1
6
4
5
3
September
5.8
3
6
7
1
October
10.0
14
5
10
6
November
16.0
10
28
15
7
December
18.1
14
40
21
13
Average
11.1
18.2
10.2
15.8
8.2
7.9
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
10.6
11
9
13
10
11
February
11.3
11
11
15
10
11
March
11.4
12
12
12
11
12
April
11.7
12
12
14
12
10
May
10.7
11
12
11
10
June
9.7
8
10
9
12
July
8.2
7
9
8
9
August
8.4
8
9
9
8
September
10.2
9
10
10
11
October
11.1
11
11
10
12
November
10.8
11
12
11
11
December
10.3
10
11
10
10
Average
10.4
11.4
9.9
11.3
10.2
10.4
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
283°
264°
299°
296°
223°
February
310°
262°
309°
258°
276°
March
348°
348°
317°
209°
308°
April
357°
353°
002°
341°
319°
May
115°
252°
275°
329°
June
090°
267°
284°
188°
July
296°
300°
206°
228°
August
335°
250°
220°
199°
September
090°
229°
231°
272°
October
320°
296°
355°
287°
November
287°
283°
266°
234°
December
292°
353°
281°
278°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.