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
73.0
61
80
75
89
80
February
82.2
81
84
89
82
85
March
86.3
93
82
76
96
91
April
89.8
96
96
86
92
89
May
94.4
94
98
93
95
June
93.5
86
94
91
97
July
96.0
97
98
93
99
August
96.0
92
95
96
99
September
96.1
96
95
98
99
October
92.7
92
98
86
94
November
88.1
93
80
88
93
December
80.9
83
92
81
88
Average
89.3
84.2
89.8
89.9
90.9
93.1
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
-1.5
0
2
-3
1
2
February
1.4
6
3
0
-2
1
March
5.5
9
5
4
10
7
April
11.9
15
15
11
13
10
May
19.7
21
22
20
17
June
25.3
25
26
27
26
July
27.6
27
28
26
29
August
26.4
25
26
28
27
September
23.0
24
23
23
21
October
15.1
15
16
18
12
November
7.2
8
10
8
12
December
2.4
6
2
3
2
Average
12.9
7.2
14.6
14.1
14.6
13.8
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
-6.5
-3
-2
-10
-4
-3
February
-7.6
-3
-5
-9
-9
-6
March
-3.1
-1
-3
-4
-1
-1
April
2.0
4
4
2
3
0
May
7.4
7
9
7
7
June
13.6
13
14
15
14
July
16.9
17
17
17
18
August
16.2
15
16
18
17
September
13.0
14
13
12
11
October
7.1
9
6
11
4
November
0.4
1
2
1
3
December
-3.3
1
-2
-2
-2
Average
4.2
-1.2
5.9
4.7
5.6
5.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
44.0
54
46
55
31
40
February
30.7
20
34
34
28
26
March
22.5
26
28
38
8
13
April
16.2
13
13
27
14
18
May
8.0
10
5
7
10
June
5.7
6
5
7
4
July
2.8
1
1
5
2
August
4.0
8
8
2
3
September
6.5
6
12
6
8
October
15.9
23
15
9
18
November
24.2
18
36
25
13
December
29.8
22
27
26
27
Average
17.1
26.5
16.5
20.1
12.5
13.6
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
7.1
7
7
9
7
7
February
8.2
8
9
10
7
9
March
8.3
8
8
8
9
9
April
8.1
9
9
9
7
8
May
6.9
6
7
7
7
June
6.4
6
8
7
7
July
6.4
6
8
6
7
August
6.2
7
6
6
7
September
6.4
6
7
7
7
October
7.1
7
7
6
8
November
7.7
8
8
8
9
December
7.1
7
7
8
8
Average
7.2
8.3
7.0
7.6
7.1
7.6
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
269°
255°
261°
261°
266°
February
262°
267°
279°
254°
270°
March
292°
321°
292°
272°
261°
April
287°
254°
254°
316°
309°
May
352°
169°
320°
360°
June
012°
267°
269°
285°
July
332°
281°
331°
316°
August
317°
317°
254°
292°
September
090°
300°
284°
248°
October
292°
250°
330°
254°
November
251°
234°
245°
242°
December
273°
199°
249°
270°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.