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
69.2
64
65
71
70
54
February
75.9
61
71
87
76
90
March
83.1
73
63
94
93
85
April
85.6
71
75
98
95
May
95.6
92
93
97
97
June
97.2
96
97
99
94
July
97.8
96
100
100
99
August
97.4
94
100
98
99
September
93.6
92
91
94
92
October
92.8
93
91
98
98
November
82.1
91
67
84
77
December
67.2
43
49
70
71
Average
85.1
65.0
80.5
86.4
90.6
88.6
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
-1.1
0
1
-1
-1
0
February
0.0
1
0
0
-1
1
March
4.6
6
1
7
6
5
April
9.3
6
8
12
10
May
16.8
18
14
16
17
June
21.5
20
21
27
20
July
29.0
28
31
31
27
August
27.9
26
31
26
28
September
22.0
20
25
22
24
October
12.8
13
17
13
14
November
4.2
5
1
6
3
December
-1.2
1
-3
0
0
Average
11.0
2.0
11.6
13.4
13.1
12.3
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
-9.2
-7
-8
-11
-9
-6
February
-10.8
-6
-12
-13
-10
-11
March
-6.1
-4
-9
-4
-8
-5
April
-3.7
-5
-4
-3
-3
May
3.2
4
3
2
3
June
6.9
7
7
9
6
July
10.2
9
12
13
9
August
9.8
10
12
10
10
September
4.5
4
6
4
4
October
-1.5
0
1
1
-1
November
-6.6
-4
-9
-3
-7
December
-9.9
-5
-8
-7
-10
Average
-2.9
-6.5
-1.2
-1.9
0.0
-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
19.9
20
22
18
22
26
February
29.5
41
28
16
30
12
March
19.0
25
35
8
9
16
April
18.3
21
36
6
7
May
10.1
12
17
6
11
June
6.4
9
9
2
17
July
0.5
0
0
1
1
August
2.0
8
1
1
0
September
4.3
9
2
3
1
October
8.2
7
7
11
3
November
13.0
12
15
11
13
December
19.3
18
31
33
16
Average
14.1
30.7
15.2
13.1
10.1
9.8
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
3.0
3
3
3
3
4
February
4.3
4
4
3
4
4
March
4.4
5
4
5
4
4
April
5.3
5
5
6
5
May
5.5
5
7
6
6
June
4.8
4
5
5
5
July
4.4
4
5
4
4
August
4.2
5
4
5
4
September
4.5
4
4
5
4
October
4.5
4
3
6
5
November
3.3
3
4
3
4
December
2.6
2
3
5
2
Average
4.3
3.9
4.1
4.4
4.6
4.2
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
206°
200°
183°
188°
174°
February
194°
203°
229°
219°
254°
March
202°
206°
262°
237°
195°
April
217°
211°
301°
218°
May
234°
252°
310°
214°
June
281°
222°
244°
243°
July
221°
248°
223°
231°
August
213°
236°
252°
245°
September
227°
246°
215°
246°
October
233°
267°
218°
245°
November
229°
204°
184°
201°
December
178°
190°
192°
201°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.