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
71.6
69
62
83
69
65
February
83.4
77
88
77
83
96
March
89.7
89
86
91
92
88
April
86.3
82
75
83
94
May
90.7
87
90
93
91
June
93.0
82
96
100
97
July
96.4
97
96
93
98
August
92.1
92
90
94
90
September
89.5
85
92
96
94
October
85.1
85
96
82
90
November
82.8
86
83
85
87
December
74.4
57
78
79
76
Average
86.2
79.3
83.6
88.2
88.5
89.9
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
-8.6
-6
-6
-10
-4
-7
February
-7.9
1
-3
-9
-10
-4
March
1.9
3
-1
0
8
3
April
7.6
8
4
10
9
May
19.2
23
18
19
17
June
25.0
26
25
28
25
July
26.4
25
26
29
27
August
24.6
25
25
27
25
September
19.9
22
21
22
18
October
10.2
12
13
15
6
November
1.5
4
2
2
5
December
-4.0
1
-5
-5
-3
Average
8.0
-1.2
11.3
9.6
11.9
10.1
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
-17.1
-14
-14
-23
-13
-15
February
-19.8
-9
-17
-24
-21
-17
March
-9.1
-8
-13
-9
-5
-7
April
-4.9
-3
-4
-1
-4
May
5.5
8
6
5
4
June
12.1
13
11
13
13
July
13.9
12
14
14
14
August
13.2
14
14
14
13
September
9.1
11
9
9
7
October
1.5
3
2
4
-2
November
-7.3
-5
-6
-6
-5
December
-13.5
-5
-13
-14
-12
Average
-3.6
-11.7
0.4
-2.6
0.1
-1.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.6
12
20
17
14
19
February
14.2
9
7
23
11
6
March
8.4
13
14
5
5
6
April
15.2
15
30
17
9
May
6.0
5
6
2
5
June
3.8
6
2
4
3
July
2.8
3
2
2
4
August
2.6
2
2
4
3
September
4.9
3
3
7
2
October
10.3
10
6
8
9
November
14.7
8
20
11
7
December
18.1
14
31
19
14
Average
10.6
11.2
8.2
10.5
8.0
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
7.0
7
6
8
6
7
February
8.2
8
7
10
8
8
March
8.6
9
8
9
9
8
April
9.0
9
10
8
9
May
8.3
8
10
8
9
June
8.1
7
9
7
9
July
6.8
6
7
6
7
August
7.0
7
5
9
7
September
7.6
7
6
8
8
October
8.2
8
7
7
9
November
8.0
9
7
9
9
December
7.1
7
5
8
7
Average
7.9
8.3
7.5
7.8
7.8
8.2
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
264°
280°
277°
268°
236°
February
270°
261°
292°
257°
273°
March
314°
336°
301°
190°
266°
April
356°
022°
325°
303°
May
126°
207°
227°
342°
June
122°
258°
262°
183°
July
293°
262°
208°
229°
August
271°
217°
217°
199°
September
118°
263°
239°
262°
October
295°
258°
160°
265°
November
262°
266°
259°
244°
December
232°
146°
253°
271°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.