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
88.4
88
90
91
89
97
February
87.6
81
83
95
90
96
March
84.8
80
76
84
84
90
April
80.5
79
75
59
83
May
82.6
91
85
74
78
June
86.4
91
97
94
82
July
83.1
79
70
96
94
August
83.1
70
89
96
79
September
93.6
94
94
91
93
October
91.6
83
87
89
95
November
85.1
94
87
83
97
December
85.8
90
74
85
86
Average
85.3
82.2
83.8
85.3
85.8
87.8
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
-13.7
-10
-11
-17
-6
-14
February
-15.8
-11
-17
-18
-8
-15
March
-7.0
-7
-5
-9
-7
-9
April
-2.7
-1
-1
1
-1
May
3.8
5
5
4
4
June
9.1
11
12
11
9
July
13.8
16
11
18
16
August
14.7
14
16
17
16
September
10.7
12
12
10
11
October
5.7
7
7
7
4
November
-2.2
-1
-2
0
-3
December
-6.8
-3
-1
-6
-5
Average
0.0
-10.8
2.2
1.6
3.5
0.9
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
-19.2
-18
-19
-23
-12
-20
February
-22.9
-17
-25
-24
-15
-22
March
-14.3
-11
-11
-15
-14
-16
April
-8.8
-6
-6
-3
-6
May
-2.4
-1
-1
0
0
June
2.6
3
4
4
3
July
7.2
10
6
8
8
August
8.2
8
9
10
9
September
5.3
6
7
5
6
October
1.8
4
3
3
1
November
-6.5
-6
-6
-3
-7
December
-11.6
-8
-6
-11
-11
Average
-6.2
-16.8
-4.3
-5.8
-3.8
-5.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
31.5
24
29
27
34
16
February
33.8
54
32
18
22
25
March
34.6
44
40
29
34
38
April
33.5
26
49
46
33
May
23.9
15
23
29
31
June
19.9
19
13
13
25
July
23.1
18
26
18
19
August
18.9
14
19
9
19
September
20.1
13
25
22
27
October
20.6
18
25
14
22
November
31.7
14
29
34
21
December
40.7
44
53
38
38
Average
28.1
41.8
22.1
26.6
24.8
26.1
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
12.7
15
12
13
11
13
February
11.9
12
13
11
10
13
March
11.9
12
8
13
13
14
April
11.0
9
11
9
13
May
10.0
9
12
10
11
June
8.9
7
9
10
10
July
7.8
5
7
8
8
August
8.3
7
8
9
8
September
10.9
8
10
11
11
October
12.1
11
13
8
14
November
13.2
13
13
11
15
December
13.8
13
13
18
12
Average
10.8
12.7
8.9
10.5
10.4
11.4
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
294°
285°
277°
320°
286°
February
308°
295°
275°
294°
286°
March
343°
335°
308°
307°
296°
April
004°
014°
027°
315°
May
337°
329°
341°
324°
June
075°
012°
338°
002°
July
066°
068°
014°
349°
August
048°
299°
297°
036°
September
314°
315°
353°
283°
October
304°
284°
334°
283°
November
275°
296°
291°
280°
December
291°
167°
299°
290°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.