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
71.8
59
65
81
70
73
February
83.4
79
92
67
91
91
March
87.0
78
76
82
97
90
April
84.7
76
70
85
97
May
91.2
89
89
94
94
June
94.2
90
94
100
96
July
94.0
95
91
95
99
August
91.4
88
93
90
95
September
88.0
87
89
95
97
October
84.5
71
92
89
89
November
81.2
89
68
91
84
December
69.5
64
69
76
69
Average
84.9
72.4
82.5
83.1
90.1
90.5
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
-8.3
-7
-6
-12
-4
-7
February
-6.3
1
-4
-10
-9
-4
March
2.2
2
0
0
8
3
April
8.4
8
5
11
8
May
18.7
22
18
20
18
June
24.2
26
23
26
25
July
25.9
23
25
28
27
August
24.3
24
25
26
25
September
19.3
21
20
22
18
October
10.0
9
13
14
5
November
1.0
3
2
3
5
December
-4.0
1
-3
-4
-3
Average
8.4
-2.8
10.5
9.3
11.7
10.0
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
-18.8
-13
-14
-24
-13
-15
February
-19.3
-10
-18
-25
-22
-19
March
-10.2
-9
-13
-11
-6
-9
April
-3.2
-3
-3
-1
-4
May
4.8
8
6
4
4
June
10.9
13
10
12
12
July
12.0
10
12
12
14
August
12.0
13
13
14
12
September
8.3
9
8
9
6
October
1.9
3
2
6
-2
November
-7.1
-5
-6
-6
-5
December
-13.5
-5
-9
-15
-12
Average
-3.3
-11.5
-1.8
-2.0
-1.6
-2.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.1
20
10
14
7
14
February
14.9
13
9
32
6
9
March
10.9
19
23
18
4
6
April
15.7
28
33
12
5
May
7.1
5
15
3
5
June
6.6
10
5
6
4
July
5.0
6
9
1
5
August
4.8
7
4
3
5
September
7.1
6
8
6
5
October
11.3
5
9
10
12
November
17.9
21
36
16
9
December
16.1
14
13
21
12
Average
10.9
17.4
11.7
15.9
7.0
7.1
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
6.3
6
6
7
6
6
February
7.2
7
7
8
7
7
March
7.9
9
8
8
8
7
April
8.3
9
9
7
9
May
7.6
8
8
7
8
June
6.9
6
8
6
8
July
5.7
5
6
5
6
August
5.8
5
5
7
6
September
6.5
6
6
6
7
October
7.0
5
8
7
7
November
7.5
8
8
8
7
December
6.0
6
3
7
6
Average
7.0
7.2
6.3
7.2
6.7
7.1
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
266°
286°
278°
258°
265°
February
292°
282°
305°
266°
274°
March
319°
355°
306°
246°
300°
April
024°
031°
359°
310°
May
076°
191°
315°
343°
June
076°
274°
276°
226°
July
299°
293°
304°
256°
August
341°
277°
240°
281°
September
101°
287°
269°
275°
October
328°
270°
110°
258°
November
275°
289°
269°
262°
December
291°
216°
256°
285°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.