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
64.7
67
54
0
72
85
February
75.5
90
85
0
87
95
March
75.1
94
81
0
93
88
April
75.9
87
0
95
91
May
77.1
94
0
92
92
June
77.2
87
0
92
98
July
80.9
98
0
95
97
August
92.1
92
84
90
97
September
91.4
91
91
97
97
October
86.4
90
97
44
96
November
76.0
97
79
0
91
December
70.2
82
71
0
97
Average
79.5
82.9
86.5
31.4
75.6
93.8
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
-3.7
-2
-1
-5
-2
0
February
-1.7
0
2
-1
-4
0
March
5.4
4
5
5
10
7
April
12.5
15
10
15
11
May
20.9
23
22
20
19
June
25.8
27
26
28
27
July
28.1
28
28
27
29
August
26.5
28
26
27
28
September
22.4
24
21
24
20
October
14.1
15
16
18
12
November
6.3
8
9
7
11
December
1.1
5
1
2
1
Average
11.9
0.6
15.0
13.5
14.3
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
-11.6
-6
-7
-17
-9
-9
February
-11.4
0
-10
-13
-17
-13
March
-4.0
-2
-5
-5
-2
-1
April
0.5
1
1
3
0
May
8.0
7
10
8
7
June
13.1
13
13
15
14
July
15.9
16
15
15
17
August
14.5
15
15
15
14
September
10.7
12
10
9
9
October
3.7
5
2
7
1
November
-4.3
-4
-3
-4
-2
December
-8.8
-3
-5
-8
-7
Average
1.8
-3.4
3.4
2.1
2.8
2.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.3
21
28
0
11
10
February
12.9
3
22
0
11
13
March
9.2
13
18
0
8
15
April
9.5
17
0
6
8
May
7.9
8
0
9
11
June
5.1
4
0
6
6
July
2.5
2
0
4
2
August
3.0
3
4
1
3
September
5.9
4
8
1
10
October
9.0
12
7
0
10
November
11.8
6
29
0
9
December
13.5
12
34
0
5
Average
8.8
13.1
11.0
5.1
4.5
8.2
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
7.1
7
6
8
6
7
February
8.0
7
8
9
7
8
March
8.2
9
8
9
9
8
April
8.8
10
10
8
9
May
7.5
6
8
7
9
June
6.6
6
7
7
7
July
5.9
6
6
6
6
August
5.7
6
5
5
6
September
6.2
6
6
6
7
October
7.4
7
7
6
8
November
7.9
7
8
8
9
December
7.1
6
7
7
7
Average
7.2
7.6
6.9
7.6
6.8
7.5
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
290°
281°
272°
311°
278°
February
248°
278°
279°
277°
284°
March
291°
348°
310°
243°
270°
April
254°
252°
281°
304°
May
005°
176°
230°
359°
June
018°
257°
244°
187°
July
271°
273°
301°
262°
August
265°
275°
223°
256°
September
138°
287°
278°
255°
October
284°
261°
336°
271°
November
258°
249°
263°
249°
December
279°
193°
269°
273°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.