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
72.6
48
71
74
89
84
February
81.0
82
86
81
78
74
March
84.9
85
80
77
95
89
April
89.0
94
92
91
88
May
91.1
97
90
95
89
June
94.0
86
97
96
98
July
96.7
95
98
91
99
August
98.3
94
99
98
99
September
96.0
99
87
99
97
October
90.6
94
98
81
92
November
91.3
92
86
93
93
December
83.3
81
77
87
86
Average
87.8
71.4
89.5
88.9
91.7
91.5
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
1.0
1
3
-1
1
4
February
3.1
6
5
3
-1
1
March
6.7
9
5
8
11
9
April
12.5
15
13
14
11
May
19.6
20
21
19
18
June
24.4
24
24
27
25
July
27.2
27
27
26
30
August
26.4
25
27
28
28
September
23.1
23
22
24
23
October
16.4
16
16
19
15
November
8.5
9
10
10
12
December
3.9
7
3
7
4
Average
13.3
5.2
14.8
14.9
15.2
14.9
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
-5.0
-4
-2
-9
-3
-2
February
-5.7
-2
-4
-6
-7
-4
March
-2.7
1
-1
-1
0
1
April
3.4
5
3
5
3
May
9.9
8
12
9
9
June
15.3
15
15
18
15
July
18.7
19
18
18
21
August
17.9
17
18
20
19
September
14.4
14
14
15
14
October
8.6
10
7
12
8
November
1.6
1
3
2
5
December
-2.6
2
-1
1
-2
Average
5.5
-2.5
7.0
6.3
7.5
7.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
43.3
63
45
45
34
33
February
33.4
22
27
46
39
34
March
25.4
28
35
30
10
20
April
20.5
18
22
14
26
May
13.1
11
12
10
16
June
8.0
11
6
6
3
July
5.9
6
6
10
5
August
5.3
7
6
5
4
September
6.9
5
17
6
6
October
18.7
25
13
16
17
November
19.9
20
21
18
15
December
32.5
33
39
19
33
Average
20.2
37.9
19.1
20.2
14.1
16.3
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
9.7
10
8
10
8
10
February
11.3
10
13
12
11
11
March
10.7
10
11
11
11
10
April
10.4
10
10
9
11
May
8.9
8
9
9
9
June
9.2
8
10
10
9
July
8.3
8
9
8
8
August
8.3
8
8
7
9
September
8.1
8
8
9
9
October
9.2
9
9
8
10
November
10.2
10
10
10
11
December
9.7
8
10
11
11
Average
9.5
10.0
9.0
9.5
9.1
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
240°
247°
259°
269°
247°
February
238°
238°
244°
239°
253°
March
238°
251°
250°
251°
226°
April
229°
239°
252°
253°
May
245°
212°
238°
242°
June
256°
239°
229°
232°
July
236°
236°
244°
237°
August
251°
240°
234°
232°
September
208°
255°
239°
226°
October
246°
223°
253°
234°
November
241°
230°
236°
238°
December
237°
234°
232°
239°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.