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
74.5
72
62
73
74
78
February
87.1
78
88
94
91
97
March
79.2
85
76
90
95
92
April
87.8
92
77
89
95
May
93.5
94
91
91
93
June
97.2
98
98
96
96
July
97.1
97
94
98
99
August
95.6
94
95
90
100
September
93.7
92
96
100
99
October
90.0
76
92
88
93
November
78.8
68
79
90
78
December
82.7
93
67
81
86
Average
87.8
78.7
86.9
88.5
91.0
92.8
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
-7.9
-7
-5
-7
-2
-6
February
-6.3
1
-4
-2
-10
0
March
1.4
0
-5
3
9
5
April
9.0
7
5
13
10
May
19.5
22
18
18
19
June
24.9
26
24
27
25
July
27.6
27
27
30
27
August
26.7
27
28
27
28
September
21.1
23
23
25
21
October
11.3
11
13
15
10
November
2.3
5
-1
5
6
December
-4.7
2
-10
-8
1
Average
9.0
-2.0
11.3
10.8
12.6
12.3
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
-15.2
-15
-14
-19
-11
-14
February
-16.2
-8
-14
-18
-20
-10
March
-9.6
-10
-15
-8
-5
-6
April
-3.4
-3
-5
-2
-4
May
5.6
8
5
4
5
June
11.5
14
11
13
12
July
13.8
12
15
15
14
August
12.3
14
13
12
12
September
7.8
10
8
8
6
October
0.2
1
2
3
-2
November
-7.0
-3
-10
-6
-7
December
-13.8
-8
-17
-18
-10
Average
-3.9
-11.1
0.1
-2.6
-1.6
-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
10.1
12
13
9
11
7
February
9.6
6
7
5
11
4
March
8.7
14
16
6
4
5
April
6.4
7
17
5
7
May
2.7
5
8
1
2
June
1.7
0
1
3
2
July
0.8
1
1
0
2
August
1.2
1
1
3
1
September
2.6
1
0
1
0
October
5.3
10
2
3
7
November
12.2
1
23
10
7
December
12.8
6
22
17
9
Average
6.2
10.7
5.1
6.8
5.0
3.8
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
9.9
11
8
12
10
9
February
10.4
11
12
13
10
10
March
10.3
10
11
13
11
10
April
11.6
12
15
11
12
May
11.1
10
14
12
11
June
9.9
7
11
10
11
July
8.4
9
9
9
9
August
8.3
9
8
10
9
September
9.8
9
11
10
11
October
11.2
11
12
12
11
November
10.3
9
13
11
10
December
9.5
9
11
10
9
Average
10.1
10.5
9.6
11.7
10.4
10.1
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
282°
280°
282°
277°
272°
February
286°
285°
296°
288°
274°
March
325°
020°
289°
256°
274°
April
008°
348°
316°
302°
May
102°
284°
248°
153°
June
060°
274°
298°
254°
July
288°
288°
139°
241°
August
304°
270°
275°
224°
September
203°
310°
278°
275°
October
324°
308°
305°
276°
November
274°
285°
277°
261°
December
285°
322°
291°
276°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.