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
74.6
68
50
80
87
85
February
79.9
86
71
74
80
81
March
84.0
82
80
77
97
90
April
90.0
94
92
94
92
May
94.5
97
90
98
95
June
94.0
82
94
96
98
July
95.5
91
95
95
96
August
94.5
92
91
91
97
September
92.1
86
83
95
94
October
90.8
89
96
83
91
November
89.0
85
85
94
93
December
77.5
59
73
86
91
Average
88.0
78.8
82.4
86.8
92.0
92.6
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
-3.4
-2
-1
-6
-3
-1
February
-1.9
3
0
-1
-3
-1
March
4.1
7
3
5
7
6
April
11.9
14
12
14
10
May
19.4
20
22
20
18
June
24.3
24
23
26
26
July
27.3
27
26
24
30
August
25.8
24
26
27
25
September
21.9
23
20
21
20
October
15.5
16
16
16
14
November
6.5
6
9
7
10
December
0.7
3
1
2
1
Average
11.7
2.8
13.3
13.2
13.2
13.6
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
-12.9
-7
-7
-21
-10
-8
February
-11.3
-7
-11
-15
-14
-11
March
-6.9
-3
-4
-5
-6
-2
April
1.6
3
2
3
0
May
7.5
6
8
7
6
June
12.7
12
13
14
13
July
16.2
17
16
15
18
August
14.8
14
15
15
15
September
10.4
11
10
10
8
October
5.1
7
2
7
3
November
-3.8
-2
0
-2
0
December
-7.0
-3
-5
-6
-4
Average
1.7
-6.1
3.6
2.0
2.8
3.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
22.1
28
33
21
12
19
February
21.4
14
35
30
19
18
March
19.3
19
30
27
8
15
April
16.2
19
18
13
13
May
10.4
10
16
4
4
June
8.7
7
11
8
4
July
5.9
8
7
8
4
August
6.0
7
6
4
11
September
6.3
4
11
7
5
October
13.5
22
10
14
13
November
14.8
10
17
15
11
December
21.9
29
28
11
20
Average
13.8
20.5
16.8
15.6
9.5
10.0
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
7.7
8
6
7
7
8
February
8.9
8
8
10
7
9
March
8.9
9
8
9
10
9
April
9.3
9
9
9
9
May
7.7
8
7
8
8
June
7.0
5
7
8
7
July
6.5
6
7
6
7
August
5.9
6
6
6
6
September
6.0
5
6
6
7
October
7.3
7
7
7
7
November
8.1
8
8
7
10
December
7.6
7
9
8
9
Average
7.6
8.0
6.8
7.6
7.2
7.8
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
249°
324°
275°
280°
246°
February
249°
277°
263°
261°
249°
March
274°
301°
269°
255°
278°
April
244°
291°
310°
278°
May
277°
294°
259°
269°
June
018°
246°
228°
247°
July
233°
239°
276°
242°
August
247°
246°
236°
261°
September
257°
289°
248°
229°
October
233°
221°
033°
235°
November
245°
236°
245°
242°
December
346°
155°
256°
249°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.