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
2025
2024
2023
2022
2021
January
85.3
65
84
78
88
91
February
81.5
78
79
76
78
80
March
86.2
86
72
82
94
April
89.3
86
92
82
91
May
92.9
86
95
97
90
June
96.6
97
90
96
100
July
99.2
99
100
99
100
August
98.6
98
100
100
96
September
90.3
92
85
76
100
October
91.4
99
74
91
96
November
85.4
95
94
72
70
December
87.7
86
91
70
88
Average
89.0
71.4
90.9
87.6
87.0
92.0
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
2025
2024
2023
2022
2021
January
1.5
-2.0
0.3
2.3
3.2
3.9
February
-2.3
-7.9
3.0
2.1
1.3
-6.5
March
5.5
5.2
1.1
8.4
9.5
April
11.1
12.9
11.1
8.0
11.4
May
17.2
15.4
20.1
16.1
16.0
June
22.7
22.3
21.3
22.6
27.1
July
28.7
28.6
27.8
29.0
31.3
August
27.8
27.8
27.6
30.3
26.8
September
22.5
25.3
22.8
25.1
24.3
October
13.7
18.6
13.8
15.0
16.0
November
6.3
6.0
10.0
0.9
11.1
December
2.9
6.4
7.7
-5.0
0.4
Average
11.5
-4.0
14.3
14.1
13.6
14.3
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2025
2024
2023
2022
2021
January
-10.9
-11.3
-13.6
-8.9
-9.3
-7.7
February
-12.2
-15.4
-7.0
-9.6
-12.9
-16.8
March
-6.3
-6.2
-9.9
-5.7
-4.7
April
-2.6
-1.9
-2.5
-3.1
-2.3
May
4.1
2.6
6.9
3.2
2.6
June
8.3
7.2
8.9
7.7
10.0
July
11.8
11.8
11.0
12.1
14.4
August
11.5
11.0
12.1
12.9
12.8
September
7.2
9.1
8.1
9.0
6.5
October
0.7
2.6
2.0
2.9
2.2
November
-5.3
-5.4
-3.5
-10.6
-2.0
December
-8.4
-4.1
-5.7
-15.0
-12.0
Average
-1.0
-13.4
0.9
1.5
0.2
0.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2025
2024
2023
2022
2021
January
13.9
30
19
18
13
5
February
19.7
23
20
23
23
21
March
11.0
13
19
20
5
April
14.6
15
13
24
15
May
8.8
21
8
9
4
June
7.0
11
13
4
3
July
1.3
2
1
2
1
August
3.0
2
4
3
6
September
7.7
10
8
7
2
October
8.8
1
17
12
5
November
11.7
9
1
27
3
December
10.7
10
10
22
12
Average
11.1
26.3
11.0
11.1
13.0
6.3
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
2025
2024
2023
2022
2021
January
8.5
9
7
8
9
10
February
8.9
8
8
10
10
9
March
8.1
7
8
9
9
April
9.1
9
8
10
8
May
8.0
9
7
9
8
June
7.4
9
5
8
6
July
6.1
6
5
6
6
August
6.8
7
8
7
8
September
7.2
8
6
7
8
October
8.8
8
7
8
9
November
9.7
8
8
10
13
December
9.0
9
8
8
10
Average
8.1
8.6
7.8
7.2
8.3
8.5
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2025
2024
2023
2022
2021
January
266°
259°
261°
256°
256°
February
253°
259°
253°
273°
260°
March
268°
293°
286°
261°
April
293°
252°
289°
287°
May
288°
085°
281°
313°
June
295°
061°
262°
326°
July
267°
269°
305°
059°
August
093°
263°
352°
292°
September
279°
278°
296°
274°
October
254°
298°
260°
258°
November
255°
262°
264°
259°
December
256°
249°
251°
249°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.