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
75.7
59
77
70
81
80
February
82.3
91
81
77
81
73
March
87.4
81
82
83
95
96
April
91.8
97
96
91
92
May
94.4
96
93
98
95
June
94.5
81
97
98
100
July
96.4
92
99
93
99
August
98.2
95
98
98
100
September
96.0
95
87
97
99
October
91.9
96
99
82
93
November
93.5
94
94
97
97
December
84.3
75
85
88
91
Average
89.7
76.8
88.7
90.6
92.2
93.6
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
2
3
-2
1
3
February
3.6
6
6
2
-1
2
March
7.1
10
5
8
10
9
April
13.2
16
13
14
10
May
20.1
20
22
20
18
June
25.2
24
26
27
26
July
27.8
27
28
26
30
August
26.7
25
28
28
27
September
23.1
23
21
23
22
October
16.8
18
16
18
15
November
8.8
9
11
9
12
December
4.0
7
3
6
4
Average
13.7
5.9
15.2
15.1
15.1
14.8
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
-6.7
-3
-1
-11
-4
-4
February
-5.2
-2
-5
-8
-8
-4
March
-2.5
1
-2
-2
-1
1
April
3.5
5
4
4
2
May
9.3
7
10
8
8
June
14.7
14
14
16
15
July
17.8
18
17
17
19
August
16.9
16
17
19
17
September
13.5
13
13
14
12
October
8.1
9
5
11
7
November
1.1
1
3
1
4
December
-2.1
2
-2
0
-2
Average
5.0
-2.4
6.5
5.4
6.4
6.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
42.9
51
49
48
41
34
February
34.9
25
34
45
40
40
March
22.6
25
31
27
11
15
April
19.8
13
20
22
23
May
11.4
11
9
8
12
June
7.0
12
5
6
3
July
6.1
8
5
8
4
August
5.4
8
5
7
2
September
6.1
6
11
6
4
October
14.7
18
8
16
14
November
19.1
19
18
17
15
December
31.3
31
27
26
27
Average
18.9
33.4
18.7
17.5
15.7
14.4
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
9.3
9
8
9
8
9
February
10.5
10
11
11
10
10
March
10.5
10
11
11
11
10
April
9.9
10
10
9
10
May
8.3
7
8
8
9
June
8.3
8
8
9
8
July
7.2
7
8
7
8
August
7.3
7
7
6
8
September
7.3
7
7
8
8
October
8.3
8
8
8
9
November
9.4
9
10
8
10
December
8.7
8
9
9
10
Average
8.8
9.7
8.3
8.8
8.4
8.9
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
263°
271°
289°
289°
265°
February
267°
265°
271°
268°
273°
March
276°
283°
277°
274°
254°
April
263°
282°
294°
296°
May
320°
302°
315°
295°
June
346°
281°
264°
282°
July
276°
271°
313°
275°
August
285°
275°
267°
269°
September
281°
287°
263°
245°
October
271°
252°
277°
254°
November
265°
247°
257°
251°
December
263°
250°
248°
257°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.