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
65
78
94
72
55
February
84.3
94
95
87
87
78
March
87.8
93
87
97
91
77
April
92.4
98
99
96
100
85
May
87.4
98
89
93
57
June
95.0
96
97
97
96
July
91.5
96
93
89
94
August
95.0
91
94
96
98
September
90.8
88
94
96
90
October
86.5
74
90
87
90
November
91.3
97
92
98
94
December
86.4
82
80
80
96
Average
88.6
88.0
90.4
92.5
90.0
84.2
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
2.6
1
6
1
2
4
February
6.6
12
9
4
1
5
March
11.2
15
11
13
10
12
April
17.6
18
20
16
19
17
May
23.5
25
24
21
21
June
28.6
29
29
29
29
July
29.1
29
29
28
30
August
27.6
28
28
29
28
September
26.9
27
25
29
26
October
19.0
19
19
19
18
November
10.8
13
12
11
14
December
6.8
8
6
10
6
Average
16.6
11.4
18.5
17.5
16.7
17.3
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
-5.2
-5
-1
-8
-5
-3
February
-3.4
0
-1
-6
-4
-3
March
1.8
4
1
2
2
3
April
6.5
9
7
6
7
5
May
13.0
12
14
12
12
June
17.5
16
18
18
17
July
19.1
19
20
19
20
August
17.5
18
17
19
17
September
14.4
14
14
16
13
October
7.9
9
6
9
6
November
0.9
2
2
1
4
December
-2.6
2
-1
1
-3
Average
6.7
1.8
7.9
7.2
7.4
7.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.3
8
11
5
15
5
February
8.3
3
3
13
15
19
March
7.6
1
6
7
9
10
April
5.2
8
1
5
0
9
May
5.1
1
6
10
4
June
2.7
2
2
4
3
July
3.3
1
6
4
5
August
2.2
6
2
0
2
September
2.2
1
5
4
1
October
6.8
5
5
8
6
November
4.1
2
5
1
2
December
4.2
0
4
5
5
Average
5.0
4.8
3.0
5.1
6.3
5.6
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
9.1
8
9
11
7
8
February
9.5
10
10
8
11
10
March
9.5
5
11
11
11
10
April
9.3
0
11
11
11
11
May
8.4
7
10
8
9
June
6.8
7
6
7
7
July
5.0
5
5
5
4
August
5.1
6
5
6
4
September
5.7
6
5
7
5
October
8.4
9
8
8
8
November
8.8
8
10
9
10
December
9.1
9
9
10
8
Average
7.6
5.4
7.9
8.0
7.8
7.7
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
250°
235°
296°
245°
235°
February
218°
233°
210°
342°
295°
March
193°
223°
227°
188°
220°
April
360°
222°
213°
197°
266°
May
114°
179°
185°
247°
June
037°
228°
218°
194°
July
238°
225°
272°
174°
August
273°
207°
219°
054°
September
176°
303°
221°
198°
October
248°
226°
240°
257°
November
230°
224°
231°
211°
December
217°
203°
210°
236°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.