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
77.6
66
72
74
84
84
February
80.2
62
76
81
88
94
March
88.9
96
81
78
96
91
April
94.5
97
82
97
100
May
95.6
91
92
97
98
June
96.7
95
93
98
96
July
92.0
71
92
96
98
August
88.6
83
89
95
98
September
87.4
82
81
96
85
October
88.9
86
83
82
86
November
80.8
86
66
85
85
December
76.3
67
73
80
84
Average
87.4
74.5
82.3
83.1
92.2
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
-3.7
-4
0
-2
0
-4
February
-3.2
0
-1
1
-5
2
March
4.5
6
3
7
6
2
April
10.1
11
8
12
9
May
18.4
23
14
16
18
June
21.0
24
21
24
18
July
23.4
25
24
25
21
August
23.1
25
26
23
21
September
17.8
20
21
18
18
October
10.2
12
15
9
7
November
1.7
3
-4
4
2
December
-4.7
2
-11
-10
1
Average
9.0
0.5
12.3
10.6
10.1
9.4
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
-10.6
-12
-7
-10
-7
-12
February
-13.9
-11
-8
-7
-14
-6
March
-7.5
-7
-10
-2
-3
-9
April
-2.1
-1
-3
-1
-3
May
4.2
6
2
3
4
June
7.4
7
7
9
7
July
9.3
9
10
10
10
August
8.6
9
10
9
8
September
4.6
4
4
6
7
October
-1.5
-2
1
0
-1
November
-5.3
-2
-10
-3
-4
December
-10.0
-4
-19
-19
-4
Average
-2.1
-10.0
0.2
-1.2
-1.2
-1.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
24.7
32
23
34
28
21
February
24.4
30
41
29
15
10
March
15.4
14
23
19
12
18
April
10.1
10
22
10
7
May
12.1
11
28
13
9
June
8.8
11
13
3
13
July
7.7
5
12
3
16
August
7.8
10
10
6
15
September
9.6
9
10
11
15
October
12.0
10
13
11
16
November
22.5
26
34
20
23
December
23.9
27
46
28
17
Average
14.7
25.3
16.3
21.1
12.0
14.4
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
2024
2023
2022
2021
2020
January
7.8
6
7
10
8
9
February
8.3
6
10
9
8
10
March
7.7
8
6
8
10
10
April
7.8
8
8
8
8
May
5.9
5
7
6
7
June
6.0
6
6
6
6
July
5.6
5
6
5
7
August
5.9
6
5
6
7
September
6.3
6
5
9
6
October
7.7
7
7
8
8
November
8.3
8
8
9
10
December
7.3
8
7
7
8
Average
6.9
6.6
6.7
6.9
7.3
7.6
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
350°
172°
181°
186°
185°
February
201°
179°
213°
190°
194°
March
178°
357°
193°
191°
191°
April
190°
191°
224°
202°
May
256°
189°
210°
357°
June
224°
210°
203°
215°
July
218°
199°
244°
203°
August
202°
192°
200°
189°
September
187°
188°
192°
188°
October
180°
198°
195°
222°
November
186°
162°
183°
183°
December
185°
185°
177°
181°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.