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
76.8
70
62
77
82
70
February
84.7
66
90
82
87
96
March
87.3
87
91
82
91
93
April
89.8
82
86
92
96
May
96.1
92
93
96
97
June
96.9
100
97
97
95
July
95.9
94
92
95
96
August
94.7
89
92
92
99
September
92.9
88
95
100
100
October
90.4
85
88
88
98
November
76.7
79
70
87
76
December
85.9
96
65
87
88
Average
88.2
74.8
87.3
86.4
91.6
92.6
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
-8.3
-9
-8
-9
-5
-8
February
-9.8
-2
-7
-9
-14
-2
March
0.4
-2
-5
-1
8
4
April
9.4
6
6
13
10
May
20.4
23
19
19
20
June
24.7
26
24
27
23
July
27.5
27
27
30
26
August
26.9
28
28
25
29
September
21.4
24
24
24
21
October
10.8
10
13
14
8
November
-1.6
2
-3
3
1
December
-6.7
1
-12
-10
-3
Average
8.3
-5.6
10.7
9.7
11.1
10.8
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
-17.0
-18
-16
-20
-14
-16
February
-19.4
-12
-17
-20
-23
-15
March
-11.6
-11
-16
-10
-6
-8
April
-4.3
-5
-3
-3
-6
May
4.8
8
5
3
4
June
10.5
13
10
11
10
July
12.5
11
13
15
13
August
11.3
12
13
12
11
September
6.4
8
7
7
6
October
-2.4
0
0
1
-3
November
-9.0
-6
-11
-7
-9
December
-15.4
-9
-20
-19
-13
Average
-4.2
-14.2
-2.7
-3.6
-2.1
-3.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
30.8
43
27
41
28
27
February
28.5
19
34
33
36
16
March
19.8
18
23
26
10
19
April
14.0
23
23
11
12
May
5.5
7
15
7
2
June
6.6
3
9
6
8
July
2.9
3
9
1
4
August
5.0
9
7
10
1
September
6.9
7
4
1
4
October
12.2
19
7
8
13
November
26.2
14
47
17
18
December
25.1
2
66
33
26
Average
15.5
26.4
13.5
20.8
12.5
11.4
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
11.1
10
10
13
11
11
February
10.5
11
11
12
12
9
March
11.9
10
11
14
12
11
April
12.4
12
14
11
13
May
11.2
10
12
12
12
June
10.8
8
11
11
13
July
9.9
10
9
9
10
August
9.4
10
9
10
10
September
10.7
10
12
11
12
October
11.6
11
11
11
13
November
11.1
11
13
11
11
December
9.9
10
11
11
9
Average
10.9
10.5
10.3
11.7
11.0
11.1
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
297°
308°
303°
211°
241°
February
241°
289°
299°
279°
252°
March
321°
124°
304°
209°
266°
April
090°
023°
323°
303°
May
103°
315°
236°
154°
June
178°
303°
285°
281°
July
298°
348°
118°
247°
August
283°
197°
321°
239°
September
161°
215°
276°
289°
October
316°
304°
200°
288°
November
249°
296°
248°
248°
December
233°
343°
266°
252°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.