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
82.7
79
82
81
93
88
February
78.8
81
81
78
76
77
March
86.6
85
92
78
88
90
April
88.7
96
92
89
92
May
95.4
93
98
95
96
June
94.6
88
98
97
93
July
94.8
91
98
90
95
August
93.6
90
92
94
92
September
92.0
84
94
90
99
October
91.2
84
90
86
94
November
88.5
94
75
96
97
December
86.5
91
97
85
83
Average
89.4
82.0
89.1
90.0
90.5
92.0
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
-2.2
-2
-1
-1
0
-4
February
-3.3
0
-5
-2
-2
-3
March
1.0
3
1
0
2
0
April
6.0
7
7
9
5
May
11.9
12
13
12
11
June
18.8
18
21
21
21
July
23.3
26
23
21
23
August
23.1
21
24
24
23
September
17.7
19
19
18
19
October
12.0
13
15
12
12
November
4.9
4
4
9
6
December
0.9
3
2
1
4
Average
8.5
0.2
9.8
10.8
10.5
9.6
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
-10.6
-11
-7
-10
-5
-12
February
-12.4
-7
-17
-12
-8
-12
March
-8.7
-4
-7
-7
-8
-10
April
-2.0
-2
0
1
-3
May
1.5
1
2
3
2
June
7.4
7
9
9
10
July
12.1
16
12
11
11
August
12.0
11
14
13
11
September
7.4
9
8
9
8
October
2.6
4
4
3
2
November
-2.3
-2
-2
2
-2
December
-6.9
-4
-4
-6
-2
Average
-1.5
-8.4
0.9
1.5
1.8
0.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
54.7
61
59
69
29
46
February
58.1
44
56
67
56
64
March
40.2
43
28
47
41
36
April
26.6
19
29
30
22
May
19.5
17
15
24
27
June
16.9
22
12
13
12
July
14.2
22
18
21
10
August
14.2
20
18
12
19
September
18.1
18
13
21
9
October
21.7
23
10
20
21
November
39.9
27
57
27
31
December
46.5
47
28
48
38
Average
30.6
48.9
27.6
28.7
26.4
25.7
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
8.4
8
8
8
8
7
February
9.3
9
8
10
9
10
March
9.9
10
9
10
10
10
April
9.3
9
8
10
11
May
8.7
9
7
9
10
June
7.8
9
7
8
8
July
7.5
7
8
8
7
August
7.2
7
7
8
8
September
8.1
7
7
9
10
October
7.4
8
8
6
8
November
8.7
7
8
8
9
December
8.4
9
10
8
7
Average
8.4
9.0
7.9
8.0
8.4
8.7
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
252°
293°
241°
284°
279°
February
264°
260°
256°
279°
245°
March
304°
009°
257°
235°
289°
April
302°
014°
048°
241°
May
268°
264°
253°
236°
June
045°
225°
228°
225°
July
212°
234°
242°
243°
August
237°
239°
241°
234°
September
286°
225°
242°
228°
October
356°
245°
010°
238°
November
248°
290°
228°
236°
December
237°
053°
254°
218°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.