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
72.2
61
65
78
77
81
February
76.9
76
73
71
74
92
March
81.3
76
73
69
94
85
April
83.1
73
83
86
86
May
92.0
96
87
92
91
June
88.8
77
85
92
95
July
91.6
86
89
88
95
August
90.5
87
87
94
89
September
91.4
89
86
94
91
October
87.7
83
86
87
93
November
83.3
85
77
85
87
December
70.8
56
66
83
69
Average
84.1
70.7
78.2
80.9
87.9
88.5
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
-4.8
-2
-1
-6
-3
-2
February
-2.6
2
0
-3
-3
-2
March
2.9
6
3
3
6
4
April
10.1
13
10
13
9
May
18.4
19
21
18
17
June
23.5
24
24
25
25
July
26.1
26
25
25
28
August
24.7
23
25
27
24
September
20.8
22
20
20
19
October
13.5
14
14
16
11
November
4.8
5
8
5
9
December
-1.7
2
1
2
0
Average
10.5
1.8
12.4
12.2
12.6
11.8
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
-12.3
-8
-7
-19
-10
-10
February
-12.8
-8
-11
-15
-14
-12
March
-7.3
-3
-6
-8
-6
-4
April
-1.5
1
-1
1
-1
May
5.4
4
8
4
5
June
11.0
12
11
13
10
July
14.1
14
13
14
16
August
13.4
13
14
16
13
September
9.4
10
10
9
9
October
4.5
6
3
8
2
November
-4.9
-4
-1
-3
-1
December
-8.5
-3
-6
-7
-6
Average
0.5
-7.8
2.4
1.1
2.2
1.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
34.9
51
44
37
22
26
February
37.1
34
53
41
37
25
March
24.2
30
39
38
11
15
April
20.8
30
26
15
20
May
10.6
11
15
9
6
June
10.3
17
15
11
4
July
6.3
8
13
10
4
August
7.7
15
14
3
7
September
7.6
9
14
8
5
October
18.0
34
28
10
16
November
23.6
31
29
22
18
December
30.4
36
43
20
34
Average
19.3
38.2
26.9
24.8
13.6
13.2
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
6.0
6
6
3
5
6
February
7.8
8
9
9
7
7
March
8.1
9
9
8
9
7
April
7.6
8
8
6
8
May
6.8
6
7
7
8
June
6.4
5
7
7
6
July
5.8
5
6
5
6
August
5.7
6
6
5
6
September
6.0
5
6
7
7
October
6.8
7
6
6
7
November
7.2
8
8
6
7
December
5.7
6
7
2
7
Average
6.8
7.5
6.6
6.8
6.1
6.7
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
212°
254°
209°
304°
259°
February
251°
226°
249°
254°
250°
March
246°
281°
247°
266°
203°
April
233°
267°
236°
266°
May
289°
194°
288°
263°
June
335°
258°
253°
259°
July
268°
254°
285°
264°
August
298°
237°
235°
269°
September
259°
270°
243°
200°
October
252°
186°
200°
215°
November
242°
240°
227°
222°
December
160°
198°
224°
279°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.