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
82.8
74
81
81
92
94
February
83.3
78
77
89
85
87
March
87.9
87
87
78
95
90
April
88.1
74
85
94
93
May
91.5
93
84
95
92
June
91.6
81
93
90
95
July
94.2
86
95
95
99
August
94.4
94
89
92
95
September
94.9
95
92
98
93
October
89.0
86
90
78
96
November
91.7
91
91
91
96
December
82.9
73
81
81
91
Average
89.1
79.6
85.0
87.6
90.9
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
-4.7
-3
-2
-6
-2
-1
February
-3.6
2
-1
-4
-5
-2
March
1.8
5
2
1
4
3
April
8.3
10
7
11
8
May
16.1
17
18
17
15
June
21.8
24
22
23
22
July
24.9
25
24
24
27
August
23.7
23
24
25
24
September
19.7
21
20
19
17
October
12.6
13
13
16
10
November
4.9
5
7
6
8
December
0.0
3
0
1
0
Average
9.5
1.1
11.7
10.8
11.7
10.6
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
-11.8
-7
-7
-16
-8
-7
February
-12.7
-7
-11
-14
-15
-11
March
-7.7
-3
-6
-7
-5
-5
April
-1.4
1
-1
1
-1
May
6.0
6
8
6
5
June
11.8
12
11
13
12
July
15.6
15
15
15
18
August
15.1
14
16
17
15
September
11.7
12
12
11
11
October
6.2
8
5
10
4
November
-2.9
-1
0
-1
2
December
-6.3
-2
-5
-5
-6
Average
1.6
-6.4
3.5
2.3
3.5
2.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
27.0
44
37
42
11
15
February
26.8
30
39
32
23
17
March
19.2
25
26
37
7
12
April
16.4
26
22
13
13
May
8.8
17
6
7
6
June
6.1
9
7
5
6
July
5.2
8
7
7
5
August
5.0
7
12
5
6
September
5.9
2
10
6
7
October
18.4
32
25
10
15
November
17.4
22
21
19
8
December
21.6
19
31
30
21
Average
15.3
32.8
19.9
19.9
10.9
10.2
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
9.5
10
10
11
8
9
February
10.7
10
13
12
9
10
March
10.7
11
12
11
11
10
April
10.2
11
11
10
11
May
8.9
8
9
9
9
June
8.4
8
10
9
8
July
8.0
7
9
8
8
August
8.4
9
9
8
8
September
8.9
8
9
10
10
October
10.1
10
10
9
10
November
11.0
12
12
10
11
December
10.3
10
11
12
11
Average
9.5
10.3
9.6
10.2
9.2
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
312°
034°
303°
347°
331°
February
289°
288°
296°
302°
281°
March
298°
331°
291°
262°
270°
April
307°
265°
313°
288°
May
296°
184°
280°
284°
June
351°
262°
222°
248°
July
265°
259°
286°
254°
August
278°
264°
219°
260°
September
138°
303°
250°
245°
October
280°
269°
038°
263°
November
271°
247°
261°
238°
December
011°
359°
286°
310°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.