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
66.7
56
55
86
66
57
February
83.7
88
78
90
79
87
March
82.5
89
73
85
82
80
April
85.1
90
87
87
95
May
90.9
93
93
92
91
June
95.9
97
97
99
99
July
96.9
99
96
92
99
August
92.8
92
89
98
98
September
93.8
90
98
96
96
October
86.6
83
100
83
88
November
88.6
97
92
93
100
December
74.6
74
58
91
80
Average
85.9
78.3
85.9
90.6
88.5
89.8
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
-5.7
-4
-5
-5
-2
-5
February
-3.6
6
-2
-3
-9
-3
March
4.5
8
0
4
10
6
April
11.6
12
9
13
13
May
20.8
23
21
20
18
June
27.4
28
27
29
28
July
27.9
27
29
28
28
August
26.4
28
27
27
27
September
23.6
26
24
24
22
October
14.2
15
17
17
11
November
6.5
9
6
8
22
December
-1.6
5
-3
1
-4
Average
11.9
3.3
13.9
13.3
14.0
14.5
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
-13.6
-11
-12
-17
-9
-12
February
-13.6
-5
-12
-15
-17
-12
March
-5.6
-4
-8
-4
-1
-2
April
1.0
1
0
2
0
May
9.3
10
9
9
8
June
16.2
16
16
16
17
July
17.0
15
18
17
18
August
15.6
16
15
16
16
September
12.0
13
11
12
9
October
3.8
5
3
7
1
November
-4.6
-3
-4
-2
10
December
-9.1
-5
-10
-9
-11
Average
1.7
-8.9
3.0
2.2
3.4
4.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.2
10
24
10
9
16
February
12.0
5
14
14
12
10
March
10.0
9
15
7
11
6
April
11.3
12
14
6
3
May
7.9
5
5
9
11
June
3.9
4
4
4
2
July
2.8
2
3
4
2
August
3.8
7
3
2
1
September
4.7
3
3
6
5
October
8.0
11
2
6
12
November
7.7
7
9
5
0
December
12.8
11
26
10
25
Average
8.1
8.1
9.0
7.1
6.7
6.6
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
10.2
10
9
11
9
10
February
10.7
11
11
14
8
11
March
11.0
12
11
11
11
11
April
12.0
14
15
13
10
May
10.0
9
11
10
11
June
8.7
7
10
8
10
July
7.0
7
8
6
7
August
7.2
8
7
8
8
September
8.5
8
9
9
10
October
9.6
11
10
9
8
November
11.3
10
13
12
11
December
9.9
9
11
11
10
Average
9.7
11.1
9.4
10.7
9.4
9.6
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
283°
296°
272°
284°
286°
February
259°
274°
294°
274°
281°
March
323°
317°
321°
190°
287°
April
289°
260°
306°
306°
May
128°
229°
183°
332°
June
154°
218°
231°
159°
July
270°
249°
195°
188°
August
227°
203°
172°
184°
September
173°
196°
211°
244°
October
300°
252°
219°
258°
November
250°
262°
265°
190°
December
259°
242°
269°
227°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.