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
36.8
27
27
43
39
29
February
34.3
29
37
41
27
51
March
50.9
43
41
43
69
58
April
57.3
57
50
80
68
May
70.3
70
45
81
66
June
75.8
86
56
90
68
July
96.6
100
92
98
92
August
90.2
82
98
83
97
September
76.1
73
76
85
68
October
66.1
66
58
65
67
November
43.7
40
42
46
32
December
33.2
41
19
19
42
Average
59.8
33.8
59.9
55.3
68.2
63.6
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
-3.3
-3
-4
-2
-3
-2
February
-4.1
-2
-4
-2
-6
-2
March
0.7
1
-2
2
2
0
April
4.1
5
2
6
5
May
11.3
15
7
11
10
June
15.6
16
14
21
14
July
22.4
22
24
25
20
August
21.7
21
24
20
22
September
15.1
14
18
15
18
October
6.5
8
10
7
6
November
-1.7
0
-4
2
0
December
-3.6
0
-5
-4
-1
Average
6.3
-2.4
7.8
7.7
8.0
7.4
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
-7.3
-8
-7
-6
-6
-6
February
-9.2
-6
-9
-8
-10
-7
March
-6.9
-5
-7
-4
-4
-6
April
-3.2
-3
-6
-2
-3
May
3.3
6
0
2
2
June
6.9
8
6
10
6
July
13.1
13
14
16
11
August
12.4
13
15
11
12
September
7.2
7
10
7
9
October
0.7
2
5
1
1
November
-5.5
-4
-8
-3
-4
December
-7.6
-4
-9
-9
-5
Average
0.0
-7.7
1.2
0.9
1.1
0.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
36.9
46
25
42
22
58
February
47.2
52
46
27
59
35
March
34.7
40
44
41
21
30
April
30.9
31
44
15
19
May
15.7
13
28
13
19
June
11.7
10
24
4
14
July
1.5
1
2
1
2
August
4.0
11
1
3
2
September
10.8
19
12
9
7
October
18.5
11
22
16
22
November
30.3
34
25
32
39
December
37.7
33
43
57
27
Average
24.7
45.5
23.3
26.1
18.7
21.2
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
3.8
3
3
4
3
5
February
4.0
3
4
3
4
5
March
3.6
2
3
3
4
4
April
3.4
2
3
4
4
May
3.0
2
3
3
4
June
3.0
2
3
3
4
July
2.7
2
2
2
3
August
2.6
2
2
2
3
September
2.9
2
3
3
3
October
3.4
2
3
3
4
November
3.8
3
3
4
5
December
3.6
4
3
3
4
Average
3.3
2.8
2.6
2.9
3.1
3.9
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
189°
180°
221°
207°
227°
February
181°
215°
214°
259°
244°
March
207°
170°
223°
227°
220°
April
249°
197°
228°
233°
May
122°
228°
238°
179°
June
270°
196°
168°
264°
July
250°
230°
273°
223°
August
208°
188°
225°
261°
September
204°
178°
216°
191°
October
201°
251°
175°
232°
November
202°
199°
210°
204°
December
189°
210°
215°
202°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.