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
90.8
84
93
96
91
91
February
86.1
92
88
92
76
92
March
86.3
82
69
92
96
88
April
90.5
94
90
90
89
92
May
91.3
95
94
100
89
95
June
98.5
100
99
50
99
95
July
99.8
100
100
100
100
100
August
98.1
100
95
97
100
September
95.8
90
98
100
96
October
88.3
82
88
95
81
November
90.4
97
85
99
94
December
88.7
96
85
85
83
Average
91.7
93.5
91.2
90.7
93.4
93.0
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
2024
2023
2022
2021
2020
January
3.1
1
4
5
5
1
February
-1.5
4
3
2
-7
4
March
5.6
5
1
8
10
6
April
11.4
14
12
9
12
10
May
17.1
17
21
17
17
17
June
23.4
23
23
18
27
23
July
29.8
31
30
31
31
28
August
28.6
31
30
27
30
September
23.3
24
25
25
23
October
12.6
13
16
17
8
November
7.2
10
3
12
9
December
3.4
9
-4
0
5
Average
11.6
14.7
14.8
8.6
14.6
13.8
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
-7.5
-10
-5
-8
-2
-8
February
-10.4
-5
-6
-9
-14
-6
March
-5.5
-4
-7
-3
-2
-4
April
0.4
3
1
-2
0
-2
May
5.4
5
9
13
4
5
June
10.4
10
12
11
10
11
July
12.1
16
13
18
8
11
August
12.9
14
15
13
12
September
9.5
11
10
10
9
October
1.9
2
6
4
-2
November
-3.1
0
-6
-1
-1
December
-7.9
-2
-13
-11
-3
Average
0.3
2.8
3.5
-3.5
1.7
1.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
11.6
12
8
8
13
14
February
22.3
15
14
19
35
14
March
14.2
18
23
14
6
17
April
15.5
8
18
19
17
16
May
9.4
13
6
0
10
5
June
5.5
8
5
50
3
7
July
0.8
1
0
0
1
2
August
3.1
1
5
5
1
September
6.1
9
5
2
3
October
13.3
16
12
6
24
November
11.8
2
19
3
4
December
13.0
6
20
24
8
Average
11.1
9.5
9.2
14.2
9.3
9.0
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
13.2
12
13
16
14
12
February
12.8
11
12
16
14
13
March
12.0
10
10
16
12
14
April
13.0
14
11
16
11
14
May
11.2
14
9
9
11
12
June
10.8
13
8
9
11
12
July
9.4
9
8
0
10
10
August
10.8
11
10
12
10
September
10.8
10
10
11
11
October
12.2
11
12
12
13
November
13.2
11
15
15
14
December
11.9
10
12
14
10
Average
12.2
12.0
10.2
14.4
11.9
11.9
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
284°
230°
280°
275°
284°
February
281°
230°
288°
276°
286°
March
262°
173°
295°
277°
293°
April
296°
281°
298°
299°
305°
May
286°
158°
267°
296°
265°
June
278°
227°
110°
292°
295°
July
278°
284°
360°
329°
288°
August
295°
285°
300°
294°
September
286°
289°
291°
309°
October
287°
290°
281°
283°
November
278°
256°
281°
276°
December
285°
237°
266°
282°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.