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
79.6
71
80
81
78
85
February
81.9
84
76
78
84
83
March
87.8
88
84
84
95
95
April
94.6
94
94
96
96
May
95.4
99
96
97
96
June
93.9
78
98
98
99
July
97.3
93
99
97
98
August
97.9
97
97
98
99
September
96.1
96
89
99
100
October
94.1
94
99
91
95
November
92.9
94
97
95
99
December
84.2
77
78
89
92
Average
90.9
81.3
88.8
91.7
93.8
95.2
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
0.8
1
3
-1
0
4
February
3.7
7
6
4
0
2
March
7.0
10
6
9
10
10
April
13.9
18
13
15
11
May
20.9
21
23
21
20
June
25.3
25
25
28
27
July
28.4
29
29
27
30
August
27.1
26
29
29
28
September
23.4
24
22
24
24
October
17.3
18
18
19
16
November
8.9
9
12
9
13
December
3.9
7
4
7
4
Average
13.9
5.8
15.9
15.8
15.9
15.8
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
-7.7
-4
-2
-12
-5
-4
February
-6.8
-3
-5
-7
-7
-5
March
-3.9
1
-2
-2
-2
0
April
3.7
6
3
5
3
May
9.3
8
10
9
9
June
14.6
15
14
17
15
July
18.3
19
18
18
20
August
17.4
17
18
20
18
September
13.3
14
13
14
12
October
8.1
10
6
11
7
November
0.9
1
4
1
3
December
-3.4
1
-2
0
-2
Average
4.8
-2.3
6.8
5.6
6.9
6.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
37.7
45
48
29
37
28
February
31.2
26
33
40
35
29
March
24.6
28
30
28
16
18
April
19.9
17
23
19
22
May
12.3
8
9
13
9
June
8.2
11
5
7
3
July
6.6
8
4
10
3
August
6.5
10
8
9
5
September
8.1
5
21
9
5
October
16.5
20
5
20
18
November
22.4
19
20
22
18
December
34.4
50
34
21
27
Average
19.2
32.5
19.9
17.2
16.7
13.7
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
8.6
8
8
8
8
9
February
9.2
9
9
11
7
9
March
9.5
9
10
10
10
9
April
9.3
9
10
9
10
May
7.3
7
7
7
8
June
7.3
7
8
7
7
July
6.5
6
7
7
7
August
6.7
7
7
6
7
September
6.3
6
7
7
7
October
7.4
7
7
7
7
November
8.7
8
10
8
9
December
8.3
8
9
8
9
Average
8.0
8.8
7.5
8.1
7.5
8.0
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
255°
276°
267°
286°
258°
February
263°
260°
248°
255°
260°
March
279°
282°
270°
271°
262°
April
256°
279°
290°
276°
May
295°
257°
291°
277°
June
319°
272°
239°
281°
July
263°
268°
295°
268°
August
267°
267°
274°
274°
September
303°
281°
248°
227°
October
250°
211°
302°
246°
November
249°
239°
253°
236°
December
273°
248°
234°
246°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.