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
74.5
73
64
79
72
77
February
80.0
76
82
72
86
93
March
88.6
88
82
95
95
86
April
88.4
82
78
88
96
May
95.2
94
95
96
98
June
97.7
93
100
98
99
July
97.2
99
99
93
99
August
94.4
94
93
97
97
September
93.1
90
97
95
96
October
92.9
91
99
96
91
November
89.3
95
82
93
93
December
72.5
58
43
82
79
Average
88.6
79.5
86.3
87.9
91.6
92.8
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
-7.4
-5
-8
-9
-3
-7
February
-6.7
5
-5
-8
-10
-5
March
2.5
6
-3
2
10
3
April
9.8
8
6
13
10
May
21.5
26
19
22
19
June
28.0
30
28
30
29
July
28.6
28
28
30
29
August
26.9
28
27
29
27
September
22.9
26
23
25
21
October
12.7
15
15
16
9
November
3.4
7
1
5
7
December
-3.3
3
-6
-4
0
Average
10.5
1.8
13.0
11.0
13.6
11.9
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
-15.4
-11
-15
-21
-10
-15
February
-16.8
-5
-17
-20
-18
-15
March
-8.9
-4
-13
-7
-3
-6
April
-1.4
-2
-2
0
-1
May
8.1
12
8
7
7
June
15.0
18
14
15
16
July
16.7
15
17
18
18
August
15.1
17
15
16
16
September
11.0
14
10
12
9
October
2.7
5
3
6
0
November
-6.8
-3
-6
-3
-4
December
-12.9
-3
-14
-13
-10
Average
0.2
-7.2
2.4
0.2
2.3
1.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
12.5
11
15
17
15
14
February
13.6
10
8
29
9
10
March
8.4
15
18
5
2
2
April
12.9
19
30
11
7
May
6.1
8
6
2
8
June
3.5
6
1
5
3
July
2.9
2
3
2
1
August
3.5
3
2
4
4
September
5.7
3
2
8
6
October
8.7
9
2
8
8
November
8.8
8
18
4
2
December
14.1
16
40
13
8
Average
8.3
11.9
9.5
11.5
6.3
5.7
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
10.3
11
9
11
10
10
February
11.1
10
11
15
10
10
March
11.2
12
12
12
11
12
April
11.9
12
14
12
11
May
10.7
11
12
10
11
June
10.1
9
11
9
12
July
8.6
8
10
8
9
August
8.5
8
9
10
9
September
9.8
8
10
10
10
October
11.0
11
11
10
12
November
11.0
11
12
11
11
December
10.4
10
12
10
10
Average
10.4
11.0
9.9
11.4
10.0
10.6
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
282°
287°
305°
297°
215°
February
285°
274°
314°
240°
269°
March
341°
354°
328°
178°
280°
April
346°
348°
343°
316°
May
159°
226°
213°
036°
June
097°
250°
254°
167°
July
301°
278°
160°
199°
August
321°
206°
195°
157°
September
109°
188°
216°
266°
October
314°
242°
104°
272°
November
273°
284°
254°
216°
December
307°
343°
258°
288°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.