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
71.8
58
65
76
80
73
February
83.9
74
91
80
91
94
March
89.3
88
79
95
98
89
April
86.1
84
67
91
95
May
92.1
92
84
91
98
June
96.3
93
97
99
99
July
97.3
98
97
95
98
August
93.5
87
95
93
95
September
92.3
88
90
96
99
October
91.1
91
98
86
94
November
85.0
89
75
86
92
December
75.2
68
48
74
89
Average
88.0
74.4
86.1
85.2
91.1
93.9
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
-8.5
-6
-8
-10
-3
-7
February
-7.0
2
-6
-9
-10
-5
March
1.1
4
-5
1
9
1
April
8.2
5
5
13
9
May
20.3
24
19
20
18
June
26.9
28
26
30
27
July
28.1
27
28
31
28
August
26.5
27
27
28
27
September
21.9
24
23
25
21
October
12.0
13
15
16
9
November
2.0
3
1
4
7
December
-4.4
1
-7
-6
0
Average
9.9
-1.7
11.3
10.6
13.2
11.2
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
-17.9
-14
-16
-21
-11
-15
February
-18.8
-7
-17
-21
-19
-16
March
-9.3
-7
-15
-8
-6
-8
April
-3.5
-4
-3
-2
-2
May
6.7
9
7
4
6
June
13.1
15
12
13
14
July
14.8
12
16
16
17
August
13.4
14
14
15
14
September
9.1
11
9
11
8
October
1.4
2
2
5
-1
November
-7.0
-6
-8
-5
-7
December
-13.2
-7
-15
-15
-11
Average
-2.9
-10.6
-1.8
-1.2
0.6
-1.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
21.3
24
27
26
19
18
February
17.0
16
11
28
17
7
March
12.0
23
19
8
3
7
April
16.9
26
35
11
10
May
6.9
5
13
3
6
June
4.2
4
4
4
4
July
2.5
3
4
1
3
August
4.2
8
4
4
3
September
5.2
5
5
6
1
October
9.1
14
6
9
6
November
16.5
10
28
10
6
December
18.5
21
45
18
6
Average
10.9
20.9
12.2
15.4
7.5
5.8
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
9.6
10
7
12
8
10
February
10.2
10
10
13
10
9
March
10.5
11
11
12
11
10
April
10.8
10
13
11
9
May
9.9
10
11
10
10
June
8.9
7
10
9
10
July
7.6
7
8
8
8
August
7.5
7
8
9
7
September
9.3
8
9
10
10
October
10.4
9
10
10
11
November
10.0
10
11
10
10
December
9.1
9
10
9
8
Average
9.5
10.2
8.7
10.6
9.5
9.4
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
287°
303°
314°
293°
265°
February
308°
312°
305°
270°
281°
March
349°
004°
317°
216°
297°
April
352°
360°
347°
317°
May
093°
285°
306°
055°
June
071°
267°
287°
194°
July
297°
307°
208°
248°
August
348°
337°
237°
258°
September
060°
334°
244°
295°
October
331°
317°
334°
308°
November
316°
306°
287°
247°
December
314°
353°
291°
288°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.