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
74.9
56
68
78
86
79
February
81.7
88
83
84
79
81
March
82.8
81
74
76
97
79
April
86.2
78
85
94
89
94
May
88.8
86
95
90
93
91
June
93.1
90
84
96
94
97
July
92.6
86
87
99
88
99
August
95.2
93
92
95
96
96
September
92.5
94
88
93
95
October
86.7
92
91
71
96
November
88.2
91
85
89
89
December
75.9
64
75
79
84
Average
87.2
82.9
84.8
88.4
88.4
90.4
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
-1.2
-1
1
-4
0
1
February
1.4
5
3
0
-2
1
March
5.5
8
4
6
10
7
April
11.7
13
14
11
13
10
May
19.2
21
19
20
19
17
June
24.3
25
23
25
26
26
July
26.9
27
26
27
25
29
August
25.6
25
24
27
27
27
September
22.1
22
22
22
21
October
15.3
16
15
17
14
November
7.4
8
10
8
11
December
2.4
5
2
4
3
Average
13.7
15.4
13.7
13.9
14.0
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
-7.3
-5
-3
-12
-5
-4
February
-7.8
-4
-5
-9
-10
-5
March
-3.1
0
-3
-3
-2
-1
April
2.1
4
3
2
2
1
May
8.1
11
7
10
7
7
June
13.8
15
14
13
15
14
July
16.5
17
16
16
16
18
August
15.8
16
15
16
17
16
September
12.5
13
12
12
11
October
6.8
8
4
10
5
November
-1.8
0
1
0
2
December
-4.8
0
-3
-2
-3
Average
4.9
6.6
5.4
4.2
5.1
4.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
33.8
44
37
36
20
25
February
29.2
13
23
41
32
28
March
22.4
27
28
27
8
18
April
19.1
26
20
17
15
18
May
12.5
11
8
15
9
15
June
8.0
10
15
7
6
3
July
5.9
7
10
4
9
3
August
4.5
7
8
5
2
5
September
5.8
6
11
6
5
October
13.9
12
9
19
15
November
17.9
16
18
16
14
December
28.0
34
39
22
25
Average
15.7
17.2
17.3
17.2
12.6
13.4
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
10.3
11
9
10
9
9
February
11.4
10
13
12
11
11
March
11.1
10
11
12
11
11
April
10.9
11
10
10
9
11
May
9.2
8
8
10
9
10
June
8.6
8
8
8
9
9
July
7.3
7
7
8
8
7
August
7.7
7
8
8
7
8
September
8.3
8
8
9
10
October
9.8
9
9
9
10
November
10.2
10
11
9
11
December
9.9
10
11
10
10
Average
9.4
8.8
9.0
9.5
9.0
9.7
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
247°
299°
263°
289°
262°
February
239°
246°
248°
260°
259°
March
257°
288°
277°
259°
296°
April
314°
255°
267°
295°
292°
May
215°
016°
036°
296°
329°
June
229°
025°
259°
234°
247°
July
233°
242°
252°
324°
252°
August
252°
281°
241°
236°
254°
September
007°
271°
251°
221°
October
236°
226°
003°
249°
November
241°
237°
241°
238°
December
305°
257°
238°
252°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.