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
92.7
99
84
92
94
95
February
81.3
74
82
69
76
86
March
87.8
83
95
88
81
78
April
94.0
93
98
86
93
May
97.6
91
100
99
98
June
91.4
98
87
88
91
July
87.1
91
85
88
84
August
90.5
91
88
89
93
September
95.8
93
94
97
100
October
96.7
100
94
99
99
November
91.1
94
83
92
93
December
81.6
64
80
67
82
Average
90.1
84.0
90.6
89.0
87.4
90.7
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
-5.1
-7
1
-7
0
-14
February
-2.5
-1
-2
0
-3
-4
March
-1.2
-3
-1
2
-2
-2
April
5.4
1
6
3
6
May
11.7
9
14
11
14
June
16.4
13
19
14
16
July
18.2
17
16
16
20
August
17.2
17
15
16
19
September
13.2
12
12
12
14
October
7.3
7
6
5
7
November
0.1
1
0
-10
0
December
-3.8
-6
-4
-4
-1
Average
5.4
-4.1
6.0
7.0
4.3
6.1
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
-12.9
-12
-5
-13
-6
-21
February
-9.6
-8
-11
-5
-10
-12
March
-9.1
-11
-10
-5
-11
-10
April
-3.7
-9
-2
-4
-1
May
3.7
3
3
4
4
June
7.5
7
8
8
7
July
10.7
9
10
11
11
August
10.4
11
10
11
10
September
6.9
5
7
7
8
October
1.7
0
0
0
3
November
-6.5
-4
-5
-16
-6
December
-9.8
-13
-10
-10
-7
Average
-2.4
-11.6
-2.9
0.2
-2.0
-2.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
11.5
5
24
15
9
6
February
21.3
36
21
30
26
16
March
14.5
22
2
17
18
24
April
11.1
5
4
13
17
May
10.9
18
2
4
8
June
9.7
13
3
12
9
July
17.3
20
20
18
14
August
21.2
21
31
15
9
September
21.8
21
34
5
12
October
15.2
3
23
19
10
November
16.4
16
26
7
10
December
20.7
29
15
25
16
Average
16.1
21.8
15.9
17.7
14.7
12.4
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
8.2
10
6
9
8
7
February
8.4
11
7
9
9
8
March
7.1
7
7
7
8
7
April
7.5
7
9
8
6
May
8.1
8
7
8
7
June
6.9
8
6
8
7
July
6.5
8
7
7
5
August
6.8
6
7
7
6
September
7.6
7
8
8
8
October
9.0
8
9
9
9
November
8.3
8
9
8
9
December
9.0
8
9
8
8
Average
7.8
9.1
7.2
7.7
7.9
7.1
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
044°
035°
017°
014°
344°
February
088°
014°
098°
042°
042°
March
079°
337°
078°
290°
326°
April
005°
086°
358°
105°
May
100°
048°
113°
104°
June
100°
143°
133°
142°
July
107°
170°
127°
233°
August
135°
156°
178°
192°
September
316°
130°
334°
087°
October
027°
023°
007°
050°
November
336°
039°
337°
017°
December
358°
015°
334°
040°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.