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
88.8
89
70
89
90
98
February
82.7
81
80
90
76
89
March
85.3
85
80
81
91
81
April
89.0
82
90
97
89
92
May
86.1
82
87
86
94
June
95.3
91
98
96
100
July
93.3
87
95
96
94
August
95.9
99
94
95
98
September
90.3
79
92
98
96
October
90.0
88
93
99
92
November
91.5
97
89
97
95
December
90.9
92
80
96
90
Average
89.5
83.9
86.2
90.7
92.4
93.3
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
4.8
3
-1
5
6
8
February
5.8
11
2
5
1
7
March
11.7
12
8
11
11
12
April
17.2
18
17
18
16
17
May
21.1
21
23
20
23
June
28.6
25
30
29
32
July
31.8
29
33
33
32
August
30.9
31
32
32
33
September
27.5
26
29
29
26
October
17.6
18
19
20
17
November
12.4
13
9
15
14
December
7.0
9
5
10
6
Average
17.2
11.2
16.7
18.7
18.6
18.9
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
-8.6
-9
-9
-8
-6
-6
February
-8.7
-3
-9
-9
-10
-7
March
-3.5
-2
-5
-4
-2
-1
April
1.1
2
1
1
0
0
May
7.4
9
7
8
7
June
13.1
13
14
14
15
July
16.6
16
18
17
17
August
15.6
16
17
16
17
September
10.7
9
12
12
10
October
2.6
4
4
4
1
November
-2.0
-1
-6
0
0
December
-6.4
-4
-8
-4
-6
Average
2.8
-4.9
3.5
3.5
4.2
3.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.5
12
14
12
6
1
February
10.5
9
18
7
17
9
March
7.3
10
6
20
4
5
April
6.8
14
5
6
4
7
May
6.7
6
7
9
3
June
2.2
7
2
1
1
July
0.6
1
1
1
1
August
1.0
1
1
1
0
September
1.5
1
2
1
4
October
4.5
6
1
2
5
November
4.0
6
9
1
3
December
6.6
12
14
2
9
Average
5.4
11.4
6.3
6.3
3.8
3.6
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
10.6
10
11
11
12
12
February
11.0
11
13
11
11
12
March
11.8
10
12
13
11
11
April
12.5
13
12
16
12
11
May
10.8
11
11
11
12
June
9.5
9
10
9
11
July
9.1
9
9
8
10
August
9.3
9
9
8
10
September
8.8
7
9
9
9
October
10.8
9
9
11
11
November
10.5
10
11
10
10
December
11.6
12
13
11
12
Average
10.6
11.0
10.1
10.8
10.3
10.8
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
321°
305°
304°
310°
306°
February
303°
290°
297°
267°
321°
March
360°
359°
342°
313°
279°
April
321°
317°
311°
339°
321°
May
112°
266°
129°
100°
June
135°
190°
144°
243°
July
087°
139°
133°
148°
August
279°
160°
191°
175°
September
336°
157°
297°
323°
October
316°
316°
298°
308°
November
311°
311°
292°
259°
December
308°
305°
263°
297°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.