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
56.0
50
52
60
60
47
February
74.8
77
84
65
74
79
March
84.9
94
80
86
93
89
April
86.7
80
70
90
93
May
89.6
91
87
74
93
June
88.2
95
96
67
98
July
96.0
96
94
94
97
August
85.4
91
60
83
91
September
83.1
87
87
98
79
October
85.2
83
89
80
91
November
74.1
80
72
79
80
December
70.7
78
43
73
78
Average
82.1
75.5
84.0
78.4
80.9
86.3
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
-9.3
-8
-8
-9
-5
-7
February
-9.3
-1
-7
-10
-12
-6
March
0.4
1
-6
0
7
2
April
7.7
3
3
12
8
May
16.1
21
17
17
18
June
20.9
27
25
19
26
July
22.9
25
26
29
27
August
25.7
25
27
25
26
September
20.6
22
21
24
21
October
10.2
11
12
14
7
November
0.2
2
-1
3
4
December
-6.8
0
-9
-8
-1
Average
7.1
-3.5
9.2
9.1
10.6
10.4
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
-18.2
-15
-17
-22
-13
-16
February
-20.9
-8
-19
-23
-22
-16
March
-10.0
-10
-16
-10
-6
-9
April
-3.1
-4
-4
-3
-3
May
4.5
8
6
3
5
June
10.2
15
12
9
13
July
11.6
11
15
15
15
August
12.1
13
13
13
12
September
8.1
10
8
10
7
October
0.5
1
1
4
-2
November
-9.5
-6
-9
-7
-7
December
-15.9
-9
-17
-17
-12
Average
-4.8
-12.8
-2.4
-2.0
-2.8
-2.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.4
11
10
10
6
10
February
6.9
7
4
11
6
5
March
4.6
8
6
4
4
4
April
8.3
15
19
6
9
May
2.3
0
5
2
2
June
1.4
1
1
1
1
July
0.5
0
2
0
1
August
1.4
1
0
3
2
September
1.7
3
1
0
1
October
6.0
9
3
5
3
November
11.6
8
17
9
5
December
8.5
5
29
5
7
Average
5.0
8.4
4.9
6.7
3.4
3.8
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
11.9
12
9
14
11
12
February
12.0
11
12
15
11
12
March
12.2
13
13
13
13
13
April
12.8
13
15
13
12
May
12.2
12
14
11
12
June
10.5
9
13
8
13
July
8.8
8
9
8
9
August
8.3
8
8
9
9
September
11.4
10
12
11
13
October
12.7
11
12
12
14
November
12.4
13
14
12
13
December
11.1
11
14
12
11
Average
11.4
12.2
10.6
12.6
10.9
11.7
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
276°
263°
285°
267°
235°
February
291°
255°
298°
266°
260°
March
333°
359°
281°
226°
247°
April
017°
016°
343°
293°
May
116°
252°
347°
162°
June
092°
265°
295°
202°
July
285°
292°
196°
242°
August
326°
273°
254°
259°
September
128°
250°
253°
270°
October
323°
304°
271°
276°
November
275°
266°
257°
234°
December
269°
335°
268°
282°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.