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
88.6
77
91
95
90
94
February
85.2
78
86
84
91
96
March
86.2
76
82
88
96
84
April
90.8
93
91
86
93
92
May
94.1
95
88
98
93
99
June
97.3
99
94
95
99
98
July
95.2
96
89
96
91
98
August
93.6
93
93
99
94
100
September
92.2
88
100
98
99
October
92.5
86
92
97
88
November
88.5
98
85
93
89
December
88.3
90
84
84
90
Average
91.5
89.2
89.7
92.3
93.5
94.2
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
0.0
-4
2
2
1
-3
February
-3.5
2
1
2
-7
3
March
3.5
2
-1
7
10
2
April
10.3
12
12
8
13
9
May
18.0
16
23
16
16
16
June
21.9
20
24
20
26
20
July
25.5
28
25
26
27
23
August
25.4
25
26
28
25
26
September
19.2
20
23
21
21
October
11.7
12
17
13
8
November
4.7
8
0
9
6
December
-1.9
6
-7
-7
4
Average
11.7
12.5
13.1
12.4
12.2
11.2
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
-10.0
-13
-7
-9
-8
-12
February
-13.7
-8
-10
-9
-16
-7
March
-8.5
-8
-11
-5
-3
-8
April
-2.7
0
-1
-3
-2
-2
May
5.5
5
8
5
4
5
June
9.6
8
10
10
11
9
July
12.5
15
12
13
14
12
August
11.6
12
12
13
12
11
September
7.0
8
9
8
8
October
0.1
1
3
0
-1
November
-6.6
-3
-9
-3
-5
December
-10.5
-4
-17
-16
-6
Average
0.3
1.2
1.3
0.7
0.0
0.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
16.3
20
12
14
15
14
February
23.8
18
23
22
25
8
March
16.9
29
22
12
6
18
April
13.9
9
10
24
15
18
May
11.8
21
5
7
15
18
June
9.2
5
10
13
8
13
July
4.5
4
4
6
2
3
August
4.6
8
4
5
6
1
September
8.6
8
4
4
1
October
10.9
13
8
7
21
November
14.7
4
23
5
11
December
15.0
11
20
25
10
Average
12.0
13.9
10.1
12.3
10.4
11.1
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
7.5
7
7
10
8
7
February
8.6
8
9
10
9
9
March
8.5
9
7
10
10
10
April
8.8
10
8
10
9
9
May
8.5
10
8
9
9
9
June
8.8
9
9
10
9
8
July
7.4
8
7
7
7
7
August
7.4
8
7
8
7
8
September
7.4
8
8
7
8
October
8.8
8
7
8
9
November
8.2
7
10
9
8
December
7.5
6
9
8
8
Average
8.1
8.7
7.6
8.7
8.3
8.3
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
039°
299°
297°
262°
283°
February
029°
287°
315°
301°
278°
March
099°
056°
316°
256°
323°
April
321°
166°
359°
330°
312°
May
328°
162°
314°
333°
356°
June
265°
331°
349°
314°
328°
July
291°
343°
124°
114°
250°
August
168°
010°
313°
344°
230°
September
220°
320°
247°
309°
October
259°
265°
248°
233°
November
278°
331°
255°
297°
December
214°
324°
316°
261°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.