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
79.6
70
75
81
80
91
February
82.8
89
82
75
82
83
March
88.0
88
83
82
97
95
April
93.1
97
86
93
96
May
94.1
96
92
94
96
June
94.3
82
94
97
99
July
95.9
95
96
95
96
August
95.4
89
94
97
98
September
94.0
95
90
95
97
October
92.2
89
99
91
92
November
89.8
90
86
90
97
December
82.9
72
75
90
87
Average
90.0
82.2
87.5
88.3
92.5
94.4
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
-1.8
0
2
-2
-1
2
February
2.4
5
3
2
-1
2
March
6.0
8
5
8
9
9
April
13.2
16
13
15
11
May
20.5
20
23
20
20
June
24.6
24
22
27
26
July
27.6
28
28
26
30
August
26.3
24
27
28
27
September
22.5
23
21
23
23
October
16.4
17
16
18
15
November
7.7
7
10
8
12
December
2.7
5
3
5
3
Average
13.0
4.2
14.5
14.7
14.8
14.9
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
-8.0
-5
-4
-14
-7
-6
February
-7.0
-5
-7
-9
-9
-7
March
-4.5
-1
-3
-4
-3
-1
April
2.4
4
2
3
2
May
8.1
6
10
7
8
June
12.7
13
10
15
13
July
16.7
17
16
16
18
August
16.0
15
17
18
16
September
12.0
11
12
13
11
October
6.8
8
4
9
6
November
-1.3
-1
1
-1
1
December
-5.7
-1
-4
-2
-4
Average
3.3
-4.5
4.7
3.8
5.0
4.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
24.5
30
29
25
19
18
February
20.4
13
23
31
22
16
March
19.6
21
27
23
10
14
April
18.2
14
23
14
16
May
10.8
6
9
11
5
June
7.5
9
8
4
2
July
6.8
9
8
11
4
August
7.8
14
9
9
6
September
6.6
2
14
7
5
October
14.0
15
6
16
15
November
15.3
9
19
18
10
December
23.3
35
32
15
17
Average
14.6
21.8
15.1
15.9
12.2
9.7
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
6
7
7
7
8
February
7.9
8
8
9
6
7
March
8.7
9
8
9
9
8
April
8.5
8
9
8
9
May
6.7
6
6
7
7
June
6.4
6
8
6
6
July
5.5
5
6
6
6
August
5.5
6
5
5
6
September
5.3
5
6
6
6
October
6.3
6
6
6
6
November
7.4
7
8
7
7
December
6.9
7
7
7
8
Average
6.9
7.5
6.5
7.0
6.5
6.9
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
253°
283°
278°
280°
272°
February
287°
259°
264°
262°
273°
March
280°
282°
287°
286°
199°
April
227°
278°
287°
277°
May
290°
181°
278°
265°
June
295°
270°
245°
274°
July
262°
282°
298°
254°
August
275°
260°
223°
267°
September
273°
272°
248°
209°
October
263°
184°
135°
225°
November
263°
252°
267°
239°
December
257°
255°
245°
263°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.