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
2025
2024
2023
2022
2021
January
82.3
79
79
82
81
93
February
78.9
79
81
81
78
76
March
86.2
83
85
92
78
88
April
89.2
93
96
92
89
May
94.7
92
92
93
98
95
June
93.5
86
88
98
97
July
95.1
97
91
98
90
August
93.7
94
90
92
94
September
92.7
97
84
94
90
October
91.8
96
84
90
86
November
88.2
86
94
75
96
December
86.1
84
91
97
85
Average
89.7
84.3
89.8
89.1
90.0
90.5
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
2025
2024
2023
2022
2021
January
-2.3
-1.9
-3.7
-1.4
-2.9
-1.9
February
-3.3
-3.0
-0.0
-6.5
-3.9
-2.5
March
1.1
2.6
2.9
1.3
0.3
2.1
April
6.2
7.7
6.7
6.9
9.0
May
12.3
13.8
13.9
12.4
13.0
12.0
June
19.0
20.1
17.8
21.1
21.0
July
23.6
25.8
25.5
23.3
20.8
August
23.2
23.6
21.3
24.1
23.8
September
17.9
19.1
18.8
19.3
18.3
October
11.9
11.5
12.5
14.6
11.5
November
5.1
6.0
3.7
3.7
8.5
December
0.9
0.8
3.0
1.8
0.5
Average
9.1
3.5
10.8
9.8
10.8
10.5
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2025
2024
2023
2022
2021
January
-9.0
-6.2
-12.9
-7.2
-10.4
-5.2
February
-12.6
-10.5
-8.9
-17.1
-12.4
-9.6
March
-8.9
-6.0
-5.7
-7.2
-7.0
-9.9
April
-2.1
-1.1
-2.3
0.1
0.9
May
1.8
2.7
3.2
1.1
2.3
2.7
June
7.6
9.1
6.9
8.6
8.8
July
12.4
14.1
16.3
12.1
10.8
August
12.1
12.5
11.0
14.0
12.9
September
7.5
8.0
8.8
8.3
9.3
October
2.6
2.5
4.2
3.6
2.5
November
-2.7
1.7
-3.7
-2.0
1.5
December
-6.8
-6.2
-4.3
-4.5
-7.5
Average
0.1
-5.5
1.8
0.9
1.5
1.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2025
2024
2023
2022
2021
January
55.1
58
61
59
69
29
February
59.2
68
44
56
67
56
March
41.0
47
43
28
47
41
April
26.8
28
19
29
30
May
20.0
20
24
17
15
24
June
18.3
28
22
12
13
July
13.7
10
22
18
21
August
14.5
16
20
18
12
September
16.4
5
18
13
21
October
22.5
28
23
10
20
November
40.0
41
27
57
27
December
47.3
52
47
28
48
Average
30.0
44.2
29.4
27.6
28.7
26.4
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
2025
2024
2023
2022
2021
January
8.5
9
8
8
8
8
February
9.3
10
9
8
10
9
March
9.7
8
10
9
10
10
April
9.4
10
9
8
10
May
8.6
9
8
9
7
9
June
7.9
8
9
7
8
July
7.5
7
7
8
8
August
7.3
8
7
7
8
September
8.0
7
7
7
9
October
7.5
8
8
8
6
November
8.7
9
7
8
8
December
8.3
8
9
10
8
Average
8.4
8.7
8.4
7.9
8.0
8.4
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2025
2024
2023
2022
2021
January
260°
252°
293°
241°
284°
February
254°
264°
260°
256°
279°
March
256°
304°
009°
257°
235°
April
041°
302°
014°
048°
May
299°
039°
268°
264°
253°
June
232°
045°
225°
228°
July
237°
212°
234°
242°
August
236°
237°
239°
241°
September
230°
286°
225°
242°
October
251°
356°
245°
010°
November
026°
248°
290°
228°
December
235°
237°
053°
254°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.