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
86.5
86
85
78
96
86
February
77.0
87
62
61
76
89
March
89.3
84
91
84
88
89
April
93.1
89
98
98
77
May
96.6
96
94
96
95
June
91.2
83
85
96
96
July
88.5
80
90
94
89
August
91.1
89
83
96
92
September
95.6
96
95
98
98
October
93.7
95
91
98
97
November
84.3
81
82
83
82
December
82.5
79
75
79
91
Average
89.5
85.2
85.9
86.2
92.7
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
2024
2023
2022
2021
2020
January
-5.0
-7
-2
-5
-2
-11
February
-3.1
-2
-3
0
-5
-3
March
0.5
1
0
3
-2
-1
April
6.8
4
6
6
6
May
12.8
12
14
12
15
June
16.0
14
18
16
16
July
17.8
15
18
17
19
August
17.5
17
16
17
19
September
13.7
12
13
12
14
October
7.8
6
6
7
8
November
-1.3
0
-2
-6
-1
December
-4.7
-6
-9
-6
-1
Average
5.6
-3.0
5.9
7.0
5.5
6.6
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
-13.1
-16
-7
-11
-8
-23
February
-12.8
-9
-11
-6
-14
-12
March
-10.4
-7
-11
-4
-15
-13
April
-3.5
-5
-3
-4
-2
May
3.5
3
3
3
4
June
7.5
8
8
7
7
July
9.9
10
10
10
10
August
9.2
9
10
8
10
September
5.4
4
7
3
6
October
0.2
-1
-1
0
-1
November
-8.7
-6
-10
-13
-8
December
-10.1
-13
-17
-15
-8
Average
-3.4
-11.2
-2.4
-1.2
-4.9
-3.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.3
10
9
21
6
8
February
15.4
8
35
24
10
11
March
10.6
21
9
14
14
10
April
5.8
13
3
2
7
May
8.0
10
1
7
5
June
7.1
16
1
6
4
July
13.3
17
15
13
12
August
14.0
14
29
8
11
September
14.2
14
17
10
11
October
12.1
7
14
11
7
November
15.3
17
14
21
9
December
17.4
23
20
17
11
Average
11.7
14.2
14.9
13.3
9.8
8.5
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
7.5
6
8
9
10
5
February
7.3
9
7
9
7
9
March
7.7
8
9
10
6
6
April
7.4
6
6
8
7
May
8.4
8
8
8
9
June
7.3
7
7
7
8
July
6.5
7
7
7
6
August
7.3
6
8
7
6
September
7.4
8
7
8
8
October
7.3
7
7
7
7
November
7.1
7
7
5
8
December
7.8
9
5
6
9
Average
7.5
7.9
7.4
7.6
7.2
7.2
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
034°
028°
023°
024°
039°
February
025°
030°
053°
032°
038°
March
018°
020°
024°
005°
020°
April
005°
011°
012°
353°
May
005°
325°
279°
002°
June
244°
218°
224°
211°
July
234°
207°
217°
221°
August
223°
183°
211°
221°
September
006°
171°
016°
037°
October
027°
028°
035°
033°
November
044°
022°
034°
028°
December
034°
026°
022°
042°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.