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
70.6
57
64
67
80
75
February
81.3
76
92
67
78
91
March
90.3
97
87
86
99
92
April
91.0
87
77
90
96
May
96.7
99
89
93
98
June
98.1
98
100
98
99
July
97.5
98
98
92
100
August
96.2
96
98
93
95
September
95.0
96
94
98
100
October
91.8
90
95
90
93
November
89.8
94
90
93
94
December
76.9
64
58
83
82
Average
89.2
78.5
90.2
86.6
91.2
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
-9.7
-6
-9
-11
-4
-7
February
-8.3
1
-7
-11
-10
-7
March
0.5
2
-5
-1
9
1
April
8.8
6
5
12
8
May
20.5
24
19
20
19
June
26.4
28
26
29
27
July
27.6
26
27
30
29
August
26.4
26
26
27
27
September
21.5
24
22
24
21
October
11.3
12
14
16
8
November
1.1
3
1
3
5
December
-5.4
0
-6
-6
-2
Average
8.8
-2.9
10.9
9.2
12.6
10.6
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
-17.2
-14
-17
-23
-13
-15
February
-19.8
-7
-19
-24
-20
-19
March
-10.5
-8
-15
-10
-5
-9
April
-2.4
-3
-2
-2
-2
May
6.7
10
8
5
5
June
13.3
15
13
14
14
July
14.5
12
16
15
16
August
13.1
14
14
14
14
September
9.5
12
9
11
8
October
1.8
3
2
5
-2
November
-8.5
-6
-8
-5
-7
December
-13.0
-7
-15
-15
-11
Average
-2.1
-10.3
0.0
-2.3
0.4
-1.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.1
8
15
15
5
16
February
8.3
7
2
17
2
5
March
5.6
10
10
3
2
4
April
8.3
12
24
8
6
May
5.5
3
9
3
6
June
3.3
2
3
3
5
July
2.2
2
5
1
2
August
2.5
5
1
3
3
September
4.3
3
4
4
1
October
8.0
12
3
8
5
November
10.5
9
12
8
6
December
10.8
5
21
12
11
Average
6.5
8.3
6.3
8.8
4.3
5.2
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
7.6
9
7
0
8
9
February
8.1
10
10
0
7
10
March
10.0
11
11
9
11
11
April
10.6
11
13
11
10
May
10.6
11
12
11
10
June
9.1
8
10
9
11
July
7.4
7
8
7
8
August
7.4
7
7
9
7
September
9.8
9
9
11
11
October
10.5
9
10
11
11
November
9.4
10
11
7
10
December
7.9
10
10
1
8
Average
9.2
10.2
9.0
8.4
8.9
9.6
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
242°
168°
360°
244°
199°
February
287°
183°
360°
257°
229°
March
335°
341°
280°
196°
216°
April
002°
006°
339°
310°
May
111°
227°
248°
136°
June
096°
295°
281°
171°
July
280°
290°
204°
226°
August
288°
225°
233°
236°
September
128°
188°
224°
275°
October
312°
270°
179°
278°
November
262°
233°
239°
215°
December
208°
345°
204°
244°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.